OBERHEIM SYNTH

>
> HELP!! im having problems with my oberheim matrix 6.
> 
> when it came to me less than half of the presets worked, the rest were just noise. so i reloaded the sounds from the original audio tape and to my absolute joy/astonishment it fixed it 100%.
> but now about 2 months later, I tried turning it on after not using it for about a week, and it wont even light up(at first). so i tried turning it off and on quickly. when i do that the display lights up and reads either "HHHHHHHHH","PWPPPPPPP","@@@@@@@@@" weird letter combinations like that(3 different combos consistently)i cant find if those are some kind of error code or not anywhere on the web.
> Its been plugged into a very good power conditioner since i've had it, so im not betting on a power surge as the culprit. i know a little bit about circuits and electronics, nothing looks burnt out on the board, nothing smells burnt. i removed every IC i could, cleaned and reseated it, but still same thing as before(on/off slowly = nothing, on/off quickly = letter combos)
> any way im just curious if any one has ever seen or heard of this before, and what it might possibly be, i couldn't find a single thing about it online!
> i love this synth, it have become my favorite one in the past couple of months, i would hate to see it die.
>

On Apr 11, 2011, at 11:55 AM, zog2zog2003 wrote:

> Mine did that when the patch-battery died.  It's a common battery.  It was spot-welded to the holder, and I mangled it.  But Radio-snack had both the battery and holder, so I put them in.
> 
> The gibberish-screen would go away if I'd load a patch bank thru midi, but would return after powering off.
> 
> 
> 
> 
> 
> --- In oberheim@yahoogroups.com, "sloppyofficial" <sloppy.hq@...> wrote:
>> 
>> HELP!! im having problems with my oberheim matrix 6.
>> 
>> when it came to me less than half of the presets worked, the rest were just noise. so i reloaded the sounds from the original audio tape and to my absolute joy/astonishment it fixed it 100%.
>> but now about 2 months later, I tried turning it on after not using it for about a week, and it wont even light up(at first). so i tried turning it off and on quickly. when i do that the display lights up and reads either "HHHHHHHHH","PWPPPPPPP","@@@@@@@@@" weird letter combinations like that(3 different combos consistently)i cant find if those are some kind of error code or not anywhere on the web.
>> Its been plugged into a very good power conditioner since i've had it, so im not betting on a power surge as the culprit. i know a little bit about circuits and electronics, nothing looks burnt out on the board, nothing smells burnt. i removed every IC i could, cleaned and reseated it, but still same thing as before(on/off slowly = nothing, on/off quickly = letter combos)
>> any way im just curious if any one has ever seen or heard of this before, and what it might possibly be, i couldn't find a single thing about it online!
>> i love this synth, it have become my favorite one in the past couple of months, i would hate to see it die.
>> 
> 
> 
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
>

>
> Did you try doing a reset?  If my memory serves me right, you hold down the STORE button and power up.
> 
> 
> On Apr 11, 2011, at 11:55 AM, zog2zog2003 wrote:
> 
> > Mine did that when the patch-battery died.  It's a common battery.  It was spot-welded to the holder, and I mangled it.  But Radio-snack had both the battery and holder, so I put them in.
> > 
> > The gibberish-screen would go away if I'd load a patch bank thru midi, but would return after powering off.
> > 
> > 
> > 
> > 
> > 
> > --- In oberheim@yahoogroups.com, "sloppyofficial" <sloppy.hq@> wrote:
> >> 
> >> HELP!! im having problems with my oberheim matrix 6.
> >> 
> >> when it came to me less than half of the presets worked, the rest were just noise. so i reloaded the sounds from the original audio tape and to my absolute joy/astonishment it fixed it 100%.
> >> but now about 2 months later, I tried turning it on after not using it for about a week, and it wont even light up(at first). so i tried turning it off and on quickly. when i do that the display lights up and reads either "HHHHHHHHH","PWPPPPPPP","@@@@@@@@@" weird letter combinations like that(3 different combos consistently)i cant find if those are some kind of error code or not anywhere on the web.
> >> Its been plugged into a very good power conditioner since i've had it, so im not betting on a power surge as the culprit. i know a little bit about circuits and electronics, nothing looks burnt out on the board, nothing smells burnt. i removed every IC i could, cleaned and reseated it, but still same thing as before(on/off slowly = nothing, on/off quickly = letter combos)
> >> any way im just curious if any one has ever seen or heard of this before, and what it might possibly be, i couldn't find a single thing about it online!
> >> i love this synth, it have become my favorite one in the past couple of months, i would hate to see it die.
> >> 
> > 
> > 
> > 
> > 
> > ------------------------------------
> > 
> > Yahoo! Groups Links
> > 
> > 
> >
>

>
> HELP!! im having problems with my oberheim matrix 6.
> 
> when it came to me less than half of the presets worked, the rest were just noise. so i reloaded the sounds from the original audio tape and to my absolute joy/astonishment it fixed it 100%.
> but now about 2 months later, I tried turning it on after not using it for about a week, and it wont even light up(at first). so i tried turning it off and on quickly. when i do that the display lights up and reads either "HHHHHHHHH","PWPPPPPPP","@@@@@@@@@" weird letter combinations like that(3 different combos consistently)i cant find if those are some kind of error code or not anywhere on the web.
> Its been plugged into a very good power conditioner since i've had it, so im not betting on a power surge as the culprit. i know a little bit about circuits and electronics, nothing looks burnt out on the board, nothing smells burnt. i removed every IC i could, cleaned and reseated it, but still same thing as before(on/off slowly = nothing, on/off quickly = letter combos)
> any way im just curious if any one has ever seen or heard of this before, and what it might possibly be, i couldn't find a single thing about it online!
> i love this synth, it have become my favorite one in the past couple of months, i would hate to see it die.
>

>
> HELP!! im having problems with my oberheim matrix 6.
> 
> when it came to me less than half of the presets worked, the rest were just noise. so i reloaded the sounds from the original audio tape and to my absolute joy/astonishment it fixed it 100%.
> but now about 2 months later, I tried turning it on after not using it for about a week, and it wont even light up(at first). so i tried turning it off and on quickly. when i do that the display lights up and reads either "HHHHHHHHH","PWPPPPPPP","@@@@@@@@@" weird letter combinations like that(3 different combos consistently)i cant find if those are some kind of error code or not anywhere on the web.
> Its been plugged into a very good power conditioner since i've had it, so im not betting on a power surge as the culprit. i know a little bit about circuits and electronics, nothing looks burnt out on the board, nothing smells burnt. i removed every IC i could, cleaned and reseated it, but still same thing as before(on/off slowly = nothing, on/off quickly = letter combos)
> any way im just curious if any one has ever seen or heard of this before, and what it might possibly be, i couldn't find a single thing about it online!
> i love this synth, it have become my favorite one in the past couple of months, i would hate to see it die.
>

>
> I don't have a Matrix 6 so don't know exactly what's wrong. What happens, if this has a back-up battery for the memory, is they go flat, then someone who doesn't know what they're doing, goes inside to investigate the problem, then they destroy the memory chips with static electricity because we all wear plastic clothes these days. I fix my synths in my birthday suit to alleviate any risk of this happening(not good if the postman knocks at the door)
> 
> Check the battery for correct voltage, check that any protection diodes are working near the battery. Check that the battery voltage (if present) is reaching the power pins of the memory chips.Look for any damage.Check the main power supply.
> 
> 
> And finally, if you don't understand anything I've said, then send your synth to a qualified professional to be repaired, or sell it. You will only make a great job of destroying a wonderful synth otherwise.Poking things with a screwdriver will not make them work again.
> 
> 
> 
> 
> ________________________________
>  From: wesleyknick <wesknick@...>
> To: oberheim@yahoogroups.com 
> Sent: Wednesday, 18 July 2012, 7:08
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
>  
> 
> Â  
> Any luck figuring a solution to your problem?  I have a Matrix 6 that does exactly the same thing.  I see you post is over a year old but I thought I'd ask anyway. 
> 
> --- In oberheim@yahoogroups.com, "sloppyofficial" <sloppy.hq@> wrote:
> >
> > HELP!! im having problems with my oberheim matrix 6.
> > 
> > when it came to me less than half of the presets worked, the rest were just noise. so i reloaded the sounds from the original audio tape and to my absolute joy/astonishment it fixed it 100%.
> > but now about 2 months later, I tried turning it on after not using it for about a week, and it wont even light up(at first). so i tried turning it off and on quickly. when i do that the display lights up and reads either "HHHHHHHHH","PWPPPPPPP","@@@@@@@@@" weird letter combinations like that(3 different combos consistently)i cant find if those are some kind of error code or not anywhere on the web.
> > Its been plugged into a very good power conditioner since i've had it, so im not betting on a power surge as the culprit. i know a little bit about circuits and electronics, nothing looks burnt out on the board, nothing smells burnt. i removed every IC i could, cleaned and reseated it, but still same thing as before(on/off slowly = nothing, on/off quickly = letter combos)
> > any way im just curious if any one has ever seen or heard of this before, and what it might possibly be, i couldn't find a single thing about it online!
> > i love this synth, it have become my favorite one in the past couple of months, i would hate to see it die.
> >
>

----- Original Message ----- 
From: wesleyknick
To: oberheim@yahoogroups.com
Sent: Wednesday, July 18, 2012 10:47 PM
Subject: [oberheim] Re: Oberheim Matrix 6, Dead?


 Most of the time it just powers on with a string of characters in the 
display and pressing the keys simply enters new characters in the display as 
though I'm typing them in.

>
> This sounds familiar...
> Isn't this part of the display CPU self-test mode functionality, or 
> something like that?
> Wasn't something like this discussed on this list about a month ago or so?
> 
> BR,
> Peter
> 
> ----- Original Message ----- 
> From: wesleyknick
> To: oberheim@yahoogroups.com
> Sent: Wednesday, July 18, 2012 10:47 PM
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> 
> 
>  Most of the time it just powers on with a string of characters in the 
> display and pressing the keys simply enters new characters in the display as 
> though I'm typing them in.
>

----- Original Message -----

From: wesleyknick

To: oberheim@yahoogroups.com

Sent: Wednesday, July 18, 2012 11:06 PM

Subject: [oberheim] Re: Oberheim Matrix 6, Dead?

I just joined the group yesterday. If you can point me to the previous discussion I'd appreciate it. The problem is it sometimes powers on without a display, other times it's limited to 7 or so characters and other times the whole diplay fills up with random characters than change when I press the keys. It seems too erratic to be a self-test mode.

--- In oberheim@yahoogroups.com, Peter Mörck wrote:
>
> This sounds familiar...
> Isn't this part of the display CPU self-test mode functionality, or
> something like that?
> Wasn't something like this discussed on this list about a month ago or so?
>
> BR,
> Peter
>
> ----- Original Message -----
> From: wesleyknick
> To: oberheim@yahoogroups.com
> Sent: Wednesday, July 18, 2012 10:47 PM
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
>
>
> Most of the time it just powers on with a string of characters in the
> display and pressing the keys simply enters new characters in the display as
> though I'm typing them in.
>

>
> I had the same problem for at least a year or so with my matrix 6. when it came to me half of the patches were normal the other half were the weird characters thing. the dude i got it from said he thought it was "some dead voice chips" i told him he was an idiot and to stick to playing guitars, then i bought it... (im dumb too i guess). one thing, mine sometimes would just be dead for a month then one day it would decide to power up and have crazy ass characters allover, or it would just power up fine to factory presets. after continuous tinkering for a year or so i have got it to power up every time into a hard reset/calibration mode, im not sure why it just jumps to calibration. In other words i cant save any patches i make unless i involve my librarian. Also i have no idea what i did to get it this far, because at this point ive tried every little possible thing to get it working right, voltages, battery, traces, wires, reseating, cleaning and psycho therapy...
> anyway its interesting to hear im not alone, hope you guys figure this out, i would love to get mine working perfectly.
> 
> 
> > Does it play OK, and you can still adjust parameters etc, only the display is problematic?
> > 
> > From: wesleyknick <wesknick@...>
> > To: oberheim@yahoogroups.com 
> > Sent: Wednesday, 18 July 2012, 22:06
> > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > 
> >  
> > I just joined the group yesterday. If you can point me to the previous discussion I'd appreciate it. The problem is it sometimes powers on without a display, other times it's limited to 7 or so characters and other times the whole diplay fills up with random characters than change when I press the keys. It seems too erratic to be a self-test mode.
> > 
> > --- In oberheim@yahoogroups.com, Peter Mörck <peter@> wrote:
> > >
> > > This sounds familiar...
> > > Isn't this part of the display CPU self-test mode functionality, or 
> > > something like that?
> > > Wasn't something like this discussed on this list about a month ago or so?
> > > 
> > > BR,
> > > Peter
> > > 
> > > ----- Original Message ----- 
> > > From: wesleyknick
> > > To: oberheim@yahoogroups.com
> > > Sent: Wednesday, July 18, 2012 10:47 PM
> > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > 
> > > 
> > > Most of the time it just powers on with a string of characters in the 
> > > display and pressing the keys simply enters new characters in the display as 
> > > though I'm typing them in.
> > >
> > 
> > 
> > 
> > 
> >
>

>
> It does play with output though after loading the factory patches they don't sound correct when compared to my fully functional Matrix 6 in addition to the garbled display.  
> 
> I went ahead and swapped the processor boards in the two synths, something not without some risk of damaging the good processor board.  Nevertheless, installing the good processor board in the originally faulty Matrix 6 resulted in a fully functional keyboard with a slightly hissy output.  Installing the suspected faulty processor board in the fully functional Matrix 6 resulted in power on problems whereby the display wouldn't light up, strange output on several of the factory patches, and a few of the keys in various places on the keyboard were non-functional.  With regard to the power on problems, I'd have to cycle the on-off switch two or three times to get the display to light up.  With the bad processor board in the 'good' Matrix 6 synth however, I didn't get a garbled display full of characters, only the display wouldn't usually light up on the first attempt at power on.  When the display did light up in was readable.  I went ahead and reloaded the original factory patches with the bad processor board however they still didn't sound correct...
> 
> --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> >
> > I had the same problem for at least a year or so with my matrix 6. when it came to me half of the patches were normal the other half were the weird characters thing. the dude i got it from said he thought it was "some dead voice chips" i told him he was an idiot and to stick to playing guitars, then i bought it... (im dumb too i guess). one thing, mine sometimes would just be dead for a month then one day it would decide to power up and have crazy ass characters allover, or it would just power up fine to factory presets. after continuous tinkering for a year or so i have got it to power up every time into a hard reset/calibration mode, im not sure why it just jumps to calibration. In other words i cant save any patches i make unless i involve my librarian. Also i have no idea what i did to get it this far, because at this point ive tried every little possible thing to get it working right, voltages, battery, traces, wires, reseating, cleaning and psycho therapy...
> > anyway its interesting to hear im not alone, hope you guys figure this out, i would love to get mine working perfectly.
> > 
> > 
> > > Does it play OK, and you can still adjust parameters etc, only the display is problematic?
> > > 
> > > From: wesleyknick <wesknick@>
> > > To: oberheim@yahoogroups.com 
> > > Sent: Wednesday, 18 July 2012, 22:06
> > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > 
> > >  
> > > I just joined the group yesterday. If you can point me to the previous discussion I'd appreciate it. The problem is it sometimes powers on without a display, other times it's limited to 7 or so characters and other times the whole diplay fills up with random characters than change when I press the keys. It seems too erratic to be a self-test mode.
> > > 
> > > --- In oberheim@yahoogroups.com, Peter Mörck <peter@> wrote:
> > > >
> > > > This sounds familiar...
> > > > Isn't this part of the display CPU self-test mode functionality, or 
> > > > something like that?
> > > > Wasn't something like this discussed on this list about a month ago or so?
> > > > 
> > > > BR,
> > > > Peter
> > > > 
> > > > ----- Original Message ----- 
> > > > From: wesleyknick
> > > > To: oberheim@yahoogroups.com
> > > > Sent: Wednesday, July 18, 2012 10:47 PM
> > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > 
> > > > 
> > > > Most of the time it just powers on with a string of characters in the 
> > > > display and pressing the keys simply enters new characters in the display as 
> > > > though I'm typing them in.
> > > >
> > > 
> > > 
> > > 
> > > 
> > >
> >
>

On Aug 2, 2012, at 8:24 PM, wesleyknick wrote:

> For anybody interested in this particular issue, that of strange 
> characters showing up in the display at power-on and those same characters 
> changing as keys are pressed (almost like a typewriter), I've determined 
> the power supply to be the problem. I had initially suspected the power 
> supply when I began looking into the issue however after checking all the 
> output voltages I had found them all to be within limits and looked 
> elsewhere. Looking elsewhere I had also suspected the RAM which included 
> my swapping out U6, U7, and U8 and still had the same problem. Again 
> suspecting the power supply and trying an alternate approach, I removed 
> the power supply board from my other fully functional Matrix 6 and 
> installed it into the problematic Matrix 6 and all issues were cleared. I 
> then proceeded to upload the original factory presets with no issues. I'm 
> not entirely sure what component is bad on the power supply, possibly the 
> +5 or +12 voltage regulators but either way I've finally narrowed down 
> what's causing the issue.
>
> The bottom line, if you display starts displaying strange characters and 
> gibberish, it's safe to say your power supply is showing inital symptons 
> of failure. I'm going to strip the bad power supply board and check all 
> the caps with an ESR tester and probably just go ahead and replace all the 
> regulators with new and it should clear the problem.
>
> Hope this helps anybody else with the same issue...
>
>
> --- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@...> wrote:
> >
> > It does play with output though after loading the factory patches they 
> > don't sound correct when compared to my fully functional Matrix 6 in 
> > addition to the garbled display.
> >
> > I went ahead and swapped the processor boards in the two synths, 
> > something not without some risk of damaging the good processor board. 
> > Nevertheless, installing the good processor board in the originally 
> > faulty Matrix 6 resulted in a fully functional keyboard with a slightly 
> > hissy output. Installing the suspected faulty processor board in the 
> > fully functional Matrix 6 resulted in power on problems whereby the 
> > display wouldn't light up, strange output on several of the factory 
> > patches, and a few of the keys in various places on the keyboard were 
> > non-functional. With regard to the power on problems, I'd have to cycle 
> > the on-off switch two or three times to get the display to light up. 
> > With the bad processor board in the 'good' Matrix 6 synth however, I 
> > didn't get a garbled display full of characters, only the display 
> > wouldn't usually light up on the first attempt at power on. When the 
> > display did light up in was readable. I went ahead and reloaded the 
> > original factory patches with the bad processor board however they still 
> > didn't sound correct...
> >
> > --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> > >
> > > I had the same problem for at least a year or so with my matrix 6. 
> > > when it came to me half of the patches were normal the other half were 
> > > the weird characters thing. the dude i got it from said he thought it 
> > > was "some dead voice chips" i told him he was an idiot and to stick to 
> > > playing guitars, then i bought it... (im dumb too i guess). one thing, 
> > > mine sometimes would just be dead for a month then one day it would 
> > > decide to power up and have crazy ass characters allover, or it would 
> > > just power up fine to factory presets. after continuous tinkering for 
> > > a year or so i have got it to power up every time into a hard 
> > > reset/calibration mode, im not sure why it just jumps to calibration. 
> > > In other words i cant save any patches i make unless i involve my 
> > > librarian. Also i have no idea what i did to get it this far, because 
> > > at this point ive tried every little possible thing to get it working 
> > > right, voltages, battery, traces, wires, reseating, cleaning and 
> > > psycho therapy...
> > > anyway its interesting to hear im not alone, hope you guys figure this 
> > > out, i would love to get mine working perfectly.
> > >
> > >
> > > > Does it play OK, and you can still adjust parameters etc, only the 
> > > > display is problematic?
> > > >
> > > > From: wesleyknick <wesknick@>
> > > > To: oberheim@yahoogroups.com
> > > > Sent: Wednesday, 18 July 2012, 22:06
> > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > >
> > > >
> > > > I just joined the group yesterday. If you can point me to the 
> > > > previous discussion I'd appreciate it. The problem is it sometimes 
> > > > powers on without a display, other times it's limited to 7 or so 
> > > > characters and other times the whole diplay fills up with random 
> > > > characters than change when I press the keys. It seems too erratic 
> > > > to be a self-test mode.
> > > >
> > > > --- In oberheim@yahoogroups.com, Peter M\ufffdrck <peter@> wrote:
> > > > >
> > > > > This sounds familiar...
> > > > > Isn't this part of the display CPU self-test mode functionality, 
> > > > > or
> > > > > something like that?
> > > > > Wasn't something like this discussed on this list about a month 
> > > > > ago or so?
> > > > >
> > > > > BR,
> > > > > Peter
> > > > >
> > > > > ----- Original Message ----- 
> > > > > From: wesleyknick
> > > > > To: oberheim@yahoogroups.com
> > > > > Sent: Wednesday, July 18, 2012 10:47 PM
> > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > >
> > > > >
> > > > > Most of the time it just powers on with a string of characters in 
> > > > > the
> > > > > display and pressing the keys simply enters new characters in the 
> > > > > display as
> > > > > though I'm typing them in.
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> >
>
>

>
> let me know if replacing the caps and regulators works. one thing i noticed is that the ground pins on the negative voltage regulators "-12v and -5v" were putting off -18v and -3v, is that normal? does yours do this?
> 
> On Aug 2, 2012, at 8:24 PM, wesleyknick wrote:
> 
> > For anybody interested in this particular issue, that of strange characters showing up in the display at power-on and those same characters changing as keys are pressed (almost like a typewriter), I've determined the power supply to be the problem. I had initially suspected the power supply when I began looking into the issue however after checking all the output voltages I had found them all to be within limits and looked elsewhere. Looking elsewhere I had also suspected the RAM which included my swapping out U6, U7, and U8 and still had the same problem. Again suspecting the power supply and trying an alternate approach, I removed the power supply board from my other fully functional Matrix 6 and installed it into the problematic Matrix 6 and all issues were cleared. I then proceeded to upload the original factory presets with no issues. I'm not entirely sure what component is bad on the power supply, possibly the +5 or +12 voltage regulators but either way I've finally narrowed down what's causing the issue.
> > 
> > The bottom line, if you display starts displaying strange characters and gibberish, it's safe to say your power supply is showing inital symptons of failure. I'm going to strip the bad power supply board and check all the caps with an ESR tester and probably just go ahead and replace all the regulators with new and it should clear the problem.
> > 
> > Hope this helps anybody else with the same issue...
> > 
> > 
> > --- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@> wrote:
> > >
> > > It does play with output though after loading the factory patches they don't sound correct when compared to my fully functional Matrix 6 in addition to the garbled display.  
> > > 
> > > I went ahead and swapped the processor boards in the two synths, something not without some risk of damaging the good processor board. Nevertheless, installing the good processor board in the originally faulty Matrix 6 resulted in a fully functional keyboard with a slightly hissy output. Installing the suspected faulty processor board in the fully functional Matrix 6 resulted in power on problems whereby the display wouldn't light up, strange output on several of the factory patches, and a few of the keys in various places on the keyboard were non-functional. With regard to the power on problems, I'd have to cycle the on-off switch two or three times to get the display to light up. With the bad processor board in the 'good' Matrix 6 synth however, I didn't get a garbled display full of characters, only the display wouldn't usually light up on the first attempt at power on. When the display did light up in was readable. I went ahead and reloaded the original factory patches with the bad processor board however they still didn't sound correct...
> > > 
> > > --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> > > >
> > > > I had the same problem for at least a year or so with my matrix 6. when it came to me half of the patches were normal the other half were the weird characters thing. the dude i got it from said he thought it was "some dead voice chips" i told him he was an idiot and to stick to playing guitars, then i bought it... (im dumb too i guess). one thing, mine sometimes would just be dead for a month then one day it would decide to power up and have crazy ass characters allover, or it would just power up fine to factory presets. after continuous tinkering for a year or so i have got it to power up every time into a hard reset/calibration mode, im not sure why it just jumps to calibration. In other words i cant save any patches i make unless i involve my librarian. Also i have no idea what i did to get it this far, because at this point ive tried every little possible thing to get it working right, voltages, battery, traces, wires, reseating, cleaning and psycho therapy...
> > > > anyway its interesting to hear im not alone, hope you guys figure this out, i would love to get mine working perfectly.
> > > > 
> > > > 
> > > > > Does it play OK, and you can still adjust parameters etc, only the display is problematic?
> > > > > 
> > > > > From: wesleyknick <wesknick@>
> > > > > To: oberheim@yahoogroups.com 
> > > > > Sent: Wednesday, 18 July 2012, 22:06
> > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > > 
> > > > > 
> > > > > I just joined the group yesterday. If you can point me to the previous discussion I'd appreciate it. The problem is it sometimes powers on without a display, other times it's limited to 7 or so characters and other times the whole diplay fills up with random characters than change when I press the keys. It seems too erratic to be a self-test mode.
> > > > > 
> > > > > --- In oberheim@yahoogroups.com, Peter Mörck <peter@> wrote:
> > > > > >
> > > > > > This sounds familiar...
> > > > > > Isn't this part of the display CPU self-test mode functionality, or 
> > > > > > something like that?
> > > > > > Wasn't something like this discussed on this list about a month ago or so?
> > > > > > 
> > > > > > BR,
> > > > > > Peter
> > > > > > 
> > > > > > ----- Original Message ----- 
> > > > > > From: wesleyknick
> > > > > > To: oberheim@yahoogroups.com
> > > > > > Sent: Wednesday, July 18, 2012 10:47 PM
> > > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > > > 
> > > > > > 
> > > > > > Most of the time it just powers on with a string of characters in the 
> > > > > > display and pressing the keys simply enters new characters in the display as 
> > > > > > though I'm typing them in.
> > > > > >
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > >
> > > >
> > >
> > 
> >
>

----- Original Message ----- 
From: "jim finch" <jahg88@...>
To: <oberheim@yahoogroups.com>
Sent: Friday, August 03, 2012 8:07 AM
Subject: [oberheim] Re: Oberheim Matrix 6, Dead?


You didn't mention how you were reading the powersupply voltages-but I 
didn't read the whole thread.If you use a O-scope you can see what is 
actually there,not just the D.C component. Most likely there is garbage 
riding on the +5V rail making the digital components see it as logic level 
shifts.

>
> You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
>

>
> You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
>

>
> You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
>

>
> Have you tested the diodes? You could upload some pictures, just in case what you think are diodes, may not be diodes. Depending on what diodes they are, modern 4148, 1n4001, 1n4004 can do the job of most oldies.The last 2 are most likely in a PS.
> 
> What about capacitors?  Electrolytics can smell a bit cat pissy if they have problems.Are you able to measure the correct voltages now?
> 
> 
> There may be a faulty decoupling ceramic capacitor near to a logic chip,or an intermittent logic chip involved in the display control. I'm guessing you may be having a 'brown out' on power up if it's the power supply.
> Power regulators don't usually have problems unless something somewhere else has made them work too hard.
> 
> 
> Sometimes it's easier to measure power at the components themselves.If a schematic says 15 volts F.I, then you can expect to find a little bit more or less on testing. But I would suspect a problem if I found 13.5v instead F.I.
> 
> 
> If you switch your Matrix on and the display is OK, does it go funny after a while?
> If you let it warm up and then do a power cycle, does the display then go funny? (try to answer these last two)
> 
> 
> 
> ________________________________
>  From: wesleyknick <wesknick@...>
> To: oberheim@yahoogroups.com 
> Sent: Sunday, 5 August 2012, 3:54
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
>  
> 
> Â  
> Assuming you were to replace the diodes on the power supply, is there a suitable substitute?  I'm having some trouble identifying the 2 different diode types visually.  6 of the diodes on the power supply are marked with what appears to be a 'T85' followed in smaller font by a '5D' or '5C'.  The two separate spherical diode types are marked with what appears to be a 'T3B5H'.  A Google search of any combination of the markings brings up very little in the way of any reference to diodes.  None of the manuals uploaded on various websites have any additional information and the only place the diodes are depicted is the block diagram.  Anybody have a parts list out there they can upload?  Most of the Korg and Roland service manuals have a parts list...
> 
> --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> >
> > You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
> >
>

>
> Have you tested the diodes? You could upload some pictures, just in case what you think are diodes, may not be diodes. Depending on what diodes they are, modern 4148, 1n4001, 1n4004 can do the job of most oldies.The last 2 are most likely in a PS.
> 
> What about capacitors?  Electrolytics can smell a bit cat pissy if they have problems.Are you able to measure the correct voltages now?
> 
> 
> There may be a faulty decoupling ceramic capacitor near to a logic chip,or an intermittent logic chip involved in the display control. I'm guessing you may be having a 'brown out' on power up if it's the power supply.
> Power regulators don't usually have problems unless something somewhere else has made them work too hard.
> 
> 
> Sometimes it's easier to measure power at the components themselves.If a schematic says 15 volts F.I, then you can expect to find a little bit more or less on testing. But I would suspect a problem if I found 13.5v instead F.I.
> 
> 
> If you switch your Matrix on and the display is OK, does it go funny after a while?
> If you let it warm up and then do a power cycle, does the display then go funny? (try to answer these last two)
> 
> 
> 
> ________________________________
>  From: wesleyknick <wesknick@...>
> To: oberheim@yahoogroups.com 
> Sent: Sunday, 5 August 2012, 3:54
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
>  
> 
> Â  
> Assuming you were to replace the diodes on the power supply, is there a suitable substitute?  I'm having some trouble identifying the 2 different diode types visually.  6 of the diodes on the power supply are marked with what appears to be a 'T85' followed in smaller font by a '5D' or '5C'.  The two separate spherical diode types are marked with what appears to be a 'T3B5H'.  A Google search of any combination of the markings brings up very little in the way of any reference to diodes.  None of the manuals uploaded on various websites have any additional information and the only place the diodes are depicted is the block diagram.  Anybody have a parts list out there they can upload?  Most of the Korg and Roland service manuals have a parts list...
> 
> --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> >
> > You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
> >
>

>
> Have you tested the diodes? You could upload some pictures, just in case what you think are diodes, may not be diodes. Depending on what diodes they are, modern 4148, 1n4001, 1n4004 can do the job of most oldies.The last 2 are most likely in a PS.
> 
> What about capacitors?  Electrolytics can smell a bit cat pissy if they have problems.Are you able to measure the correct voltages now?
> 
> 
> There may be a faulty decoupling ceramic capacitor near to a logic chip,or an intermittent logic chip involved in the display control. I'm guessing you may be having a 'brown out' on power up if it's the power supply.
> Power regulators don't usually have problems unless something somewhere else has made them work too hard.
> 
> 
> Sometimes it's easier to measure power at the components themselves.If a schematic says 15 volts F.I, then you can expect to find a little bit more or less on testing. But I would suspect a problem if I found 13.5v instead F.I.
> 
> 
> If you switch your Matrix on and the display is OK, does it go funny after a while?
> If you let it warm up and then do a power cycle, does the display then go funny? (try to answer these last two)
> 
> 
> 
> ________________________________
>  From: wesleyknick <wesknick@...>
> To: oberheim@yahoogroups.com 
> Sent: Sunday, 5 August 2012, 3:54
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> 
> 
> Â  
> Assuming you were to replace the diodes on the power supply, is there a suitable substitute?  I'm having some trouble identifying the 2 different diode types visually.  6 of the diodes on the power supply are marked with what appears to be a 'T85' followed in smaller font by a '5D' or '5C'.  The two separate spherical diode types are marked with what appears to be a 'T3B5H'.  A Google search of any combination of the markings brings up very little in the way of any reference to diodes.  None of the manuals uploaded on various websites have any additional information and the only place the diodes are depicted is the block diagram.  Anybody have a parts list out there they can upload?  Most of the Korg and Roland service manuals have a parts list...
> 
> --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> >
> > You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
> >
>

>
> Have you tested the diodes? You could upload some pictures, just in case what you think are diodes, may not be diodes. Depending on what diodes they are, modern 4148, 1n4001, 1n4004 can do the job of most oldies.The last 2 are most likely in a PS.
> 
> What about capacitors?  Electrolytics can smell a bit cat pissy if they have problems.Are you able to measure the correct voltages now?
> 
> 
> There may be a faulty decoupling ceramic capacitor near to a logic chip,or an intermittent logic chip involved in the display control. I'm guessing you may be having a 'brown out' on power up if it's the power supply.
> Power regulators don't usually have problems unless something somewhere else has made them work too hard.
> 
> 
> Sometimes it's easier to measure power at the components themselves.If a schematic says 15 volts F.I, then you can expect to find a little bit more or less on testing. But I would suspect a problem if I found 13.5v instead F.I.
> 
> 
> If you switch your Matrix on and the display is OK, does it go funny after a while?
> If you let it warm up and then do a power cycle, does the display then go funny? (try to answer these last two)
> 
> 
> 
> ________________________________
>  From: wesleyknick <wesknick@...>
> To: oberheim@yahoogroups.com 
> Sent: Sunday, 5 August 2012, 3:54
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> 
> 
> Â  
> Assuming you were to replace the diodes on the power supply, is there a suitable substitute?  I'm having some trouble identifying the 2 different diode types visually.  6 of the diodes on the power supply are marked with what appears to be a 'T85' followed in smaller font by a '5D' or '5C'.  The two separate spherical diode types are marked with what appears to be a 'T3B5H'.  A Google search of any combination of the markings brings up very little in the way of any reference to diodes.  None of the manuals uploaded on various websites have any additional information and the only place the diodes are depicted is the block diagram.  Anybody have a parts list out there they can upload?  Most of the Korg and Roland service manuals have a parts list...
> 
> --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> >
> > You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
> >
>

>
> I thought I was being modern with F.I, which in my head means for instance. Oh well that was a fail.
> 
> A brown out is when a processor doesn't get enough power I think. Usually when you switch something on like a Matrix you get a certain amount of clock cycles holding the main processor at reset, so it doesn't switch on until the power supply is stabilised, so you don't get a brown out. Some Roland TR-909's had a problem like this back in the day.
> 
> 
> If you are having problems after a warm up period then it sounds like you have a 'chip' problem. Something connected with the display circuits then, if everything else works even though the display is garbled.Maybe you can feel a chip that's a lot hotter than the others but this doesn't always give an indication.
> 
> 
> 
> 
> 
> ________________________________
>  From: wesleyknick <wesknick@...>
> To: oberheim@yahoogroups.com 
> Sent: Sunday, 5 August 2012, 16:09
> Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> 
> 
> Â  
> I haven't as of yet tested the diodes either.  I'm thinking it may be more trouble than just figuring out what to replace them with, getting the new diodes and putting them in... 
> 
> --- In oberheim@yahoogroups.com, Martin Ator <cyllall@> wrote:
> >
> > Have you tested the diodes? You could upload some pictures, just in case what you think are diodes, may not be diodes. Depending on what diodes they are, modern 4148, 1n4001, 1n4004 can do the job of most oldies.The last 2 are most likely in a PS.
> > 
> > What about capacitors?  Electrolytics can smell a bit cat pissy if they have problems.Are you able to measure the correct voltages now?
> > 
> > 
> > There may be a faulty decoupling ceramic capacitor near to a logic chip,or an intermittent logic chip involved in the display control. I'm guessing you may be having a 'brown out' on power up if it's the power supply.
> > Power regulators don't usually have problems unless something somewhere else has made them work too hard.
> > 
> > 
> > Sometimes it's easier to measure power at the components themselves.If a schematic says 15 volts F.I, then you can expect to find a little bit more or less on testing. But I would suspect a problem if I found 13.5v instead F.I.
> > 
> > 
> > If you switch your Matrix on and the display is OK, does it go funny after a while?
> > If you let it warm up and then do a power cycle, does the display then go funny? (try to answer these last two)
> > 
> > 
> > 
> > ________________________________
> >  From: wesleyknick <wesknick@>
> > To: oberheim@...m 
> > Sent: Sunday, 5 August 2012, 3:54
> > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > 
> > 
> >   
> > Assuming you were to replace the diodes on the power supply, is there a suitable substitute?  I'm having some trouble identifying the 2 different diode types visually.  6 of the diodes on the power supply are marked with what appears to be a 'T85' followed in smaller font by a '5D' or '5C'.  The two separate spherical diode types are marked with what appears to be a 'T3B5H'.  A Google search of any combination of the markings brings up very little in the way of any reference to diodes.  None of the manuals uploaded on various websites have any additional information and the only place the diodes are depicted is the block diagram.  Anybody have a parts list out there they can upload?  Most of the Korg and Roland service manuals have a parts list...
> > 
> > --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> > >
> > > You didn't mention how you were reading the powersupply voltages-but I didn't read the whole thread.If you use a O-scope you can see what is actually there,not just the D.C component. Most likely there is garbage riding on the +5V rail making the digital components see it as logic level shifts.
> > >
> >
>

----- Original Message -----

From: mrspring_eire

To: oberheim@yahoogroups.com

Sent: Wednesday, October 10, 2012 6:01 AM

Subject: [oberheim] Re: Oberheim Matrix 6, Dead?

You mean lots of: @@@@@@@@@ in the display? and they move or change when you hit keys? You need to check the following:

* Battery voltage - replace if < 3v
* output of all regulators - replace if > +/- 10%, re-grease and
check the isolating strip(s) (etc.) while You are at it
* replace caps in PSU if the have 'glue' around the base, or bulges
in the tops of them
* re-seat the OS eeprom - take it out & clean it's legs, then put it back in <-- this fixes most machines straight away but You may have
corrupt patches, so...
* re-upload the patches via audio or midi dump

this has fixed 2 of my m6s, one of which was so unhappy there was
a sticker on it with the 'calibration' procedure detailed, as
the previous owner had to do this every boot time to make it useable.

It's not clear why this is so common, but it's probable each issue causes/exasperates the others, starting with the crappy PSU design..

--- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@...> wrote:
>
> For anybody interested in this particular issue, that of strange characters showing up in the display at power-on and those same characters changing as keys are pressed (almost like a typewriter)

>
> Just by coincidence, my synth is exhibiting exactly these symptoms.  Your email is so very timely, and will no doubt help my keyboard technician get the problem resolved.  Many thanks for sharing your knowledge here on this forum to keep these vintage instruments in top form.  Best wishes!
> 
> 
>   ----- Original Message ----- 
>   From: mrspring_eire 
>   To: oberheim@yahoogroups.com 
>   Sent: Wednesday, October 10, 2012 6:01 AM
>   Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> 
> 
>     
>   You mean lots of: @@@@@@@@@ in the display? and they move or change when you hit keys? You need to check the following:
> 
>   * Battery voltage - replace if < 3v
>   * output of all regulators - replace if > +/- 10%, re-grease and
>   check the isolating strip(s) (etc.) while You are at it
>   * replace caps in PSU if the have 'glue' around the base, or bulges
>   in the tops of them
>   * re-seat the OS eeprom - take it out & clean it's legs, then put it back in <-- this fixes most machines straight away but You may have
>   corrupt patches, so...
>   * re-upload the patches via audio or midi dump
> 
>   this has fixed 2 of my m6s, one of which was so unhappy there was
>   a sticker on it with the 'calibration' procedure detailed, as
>   the previous owner had to do this every boot time to make it useable.
> 
>   It's not clear why this is so common, but it's probable each issue causes/exasperates the others, starting with the crappy PSU design..
> 
>   --- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@> wrote:
>   >
>   > For anybody interested in this particular issue, that of strange characters showing up in the display at power-on and those same characters changing as keys are pressed (almost like a typewriter)
>

>
> Yes, for now I just replaced the two 7805 and the single 7812 and threw the power supply board back in to see what it would do and now the display comes up normal at power-on.  I had to order a 7912 regulator and have some 7905s hidden somewhere I have to locate but for the most part at least replacing the 7805s and 7812 seems to have fixed the problem.  I haven't had a chance to measure the actual output with the new 7812 and 7805 regulators yet.  I haven't seen -18v nor -3v on the ground pins.  When I get a chance I'll look and see if I can see the same thing.  
> 
> --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> >
> > let me know if replacing the caps and regulators works. one thing i noticed is that the ground pins on the negative voltage regulators "-12v and -5v" were putting off -18v and -3v, is that normal? does yours do this?
> > 
> > On Aug 2, 2012, at 8:24 PM, wesleyknick wrote:
> > 
> > > For anybody interested in this particular issue, that of strange characters showing up in the display at power-on and those same characters changing as keys are pressed (almost like a typewriter), I've determined the power supply to be the problem. I had initially suspected the power supply when I began looking into the issue however after checking all the output voltages I had found them all to be within limits and looked elsewhere. Looking elsewhere I had also suspected the RAM which included my swapping out U6, U7, and U8 and still had the same problem. Again suspecting the power supply and trying an alternate approach, I removed the power supply board from my other fully functional Matrix 6 and installed it into the problematic Matrix 6 and all issues were cleared. I then proceeded to upload the original factory presets with no issues. I'm not entirely sure what component is bad on the power supply, possibly the +5 or +12 voltage regulators but either way I've finally narrowed down what's causing the issue.
> > > 
> > > The bottom line, if you display starts displaying strange characters and gibberish, it's safe to say your power supply is showing inital symptons of failure. I'm going to strip the bad power supply board and check all the caps with an ESR tester and probably just go ahead and replace all the regulators with new and it should clear the problem.
> > > 
> > > Hope this helps anybody else with the same issue...
> > > 
> > > 
> > > --- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@> wrote:
> > > >
> > > > It does play with output though after loading the factory patches they don't sound correct when compared to my fully functional Matrix 6 in addition to the garbled display.  
> > > > 
> > > > I went ahead and swapped the processor boards in the two synths, something not without some risk of damaging the good processor board. Nevertheless, installing the good processor board in the originally faulty Matrix 6 resulted in a fully functional keyboard with a slightly hissy output. Installing the suspected faulty processor board in the fully functional Matrix 6 resulted in power on problems whereby the display wouldn't light up, strange output on several of the factory patches, and a few of the keys in various places on the keyboard were non-functional. With regard to the power on problems, I'd have to cycle the on-off switch two or three times to get the display to light up. With the bad processor board in the 'good' Matrix 6 synth however, I didn't get a garbled display full of characters, only the display wouldn't usually light up on the first attempt at power on. When the display did light up in was readable. I went ahead and reloaded the original factory patches with the bad processor board however they still didn't sound correct...
> > > > 
> > > > --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> > > > >
> > > > > I had the same problem for at least a year or so with my matrix 6. when it came to me half of the patches were normal the other half were the weird characters thing. the dude i got it from said he thought it was "some dead voice chips" i told him he was an idiot and to stick to playing guitars, then i bought it... (im dumb too i guess). one thing, mine sometimes would just be dead for a month then one day it would decide to power up and have crazy ass characters allover, or it would just power up fine to factory presets. after continuous tinkering for a year or so i have got it to power up every time into a hard reset/calibration mode, im not sure why it just jumps to calibration. In other words i cant save any patches i make unless i involve my librarian. Also i have no idea what i did to get it this far, because at this point ive tried every little possible thing to get it working right, voltages, battery, traces, wires, reseating, cleaning and psycho therapy...
> > > > > anyway its interesting to hear im not alone, hope you guys figure this out, i would love to get mine working perfectly.
> > > > > 
> > > > > 
> > > > > > Does it play OK, and you can still adjust parameters etc, only the display is problematic?
> > > > > > 
> > > > > > From: wesleyknick <wesknick@>
> > > > > > To: oberheim@yahoogroups.com 
> > > > > > Sent: Wednesday, 18 July 2012, 22:06
> > > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > > > 
> > > > > > 
> > > > > > I just joined the group yesterday. If you can point me to the previous discussion I'd appreciate it. The problem is it sometimes powers on without a display, other times it's limited to 7 or so characters and other times the whole diplay fills up with random characters than change when I press the keys. It seems too erratic to be a self-test mode.
> > > > > > 
> > > > > > --- In oberheim@yahoogroups.com, Peter Mörck <peter@> wrote:
> > > > > > >
> > > > > > > This sounds familiar...
> > > > > > > Isn't this part of the display CPU self-test mode functionality, or 
> > > > > > > something like that?
> > > > > > > Wasn't something like this discussed on this list about a month ago or so?
> > > > > > > 
> > > > > > > BR,
> > > > > > > Peter
> > > > > > > 
> > > > > > > ----- Original Message ----- 
> > > > > > > From: wesleyknick
> > > > > > > To: oberheim@yahoogroups.com
> > > > > > > Sent: Wednesday, July 18, 2012 10:47 PM
> > > > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > > > > 
> > > > > > > 
> > > > > > > Most of the time it just powers on with a string of characters in the 
> > > > > > > display and pressing the keys simply enters new characters in the display as 
> > > > > > > though I'm typing them in.
> > > > > > >
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > >
> > > > >
> > > >
> > > 
> > >
> >
>

>
> Hi, I'd like to know if the 7805 replacement did work since the change.
> Mines matrix is having the same issue
> 
> Thanks
> 
> --- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@> wrote:
> >
> > Yes, for now I just replaced the two 7805 and the single 7812 and threw the power supply board back in to see what it would do and now the display comes up normal at power-on.  I had to order a 7912 regulator and have some 7905s hidden somewhere I have to locate but for the most part at least replacing the 7805s and 7812 seems to have fixed the problem.  I haven't had a chance to measure the actual output with the new 7812 and 7805 regulators yet.  I haven't seen -18v nor -3v on the ground pins.  When I get a chance I'll look and see if I can see the same thing.  
> > 
> > --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> > >
> > > let me know if replacing the caps and regulators works. one thing i noticed is that the ground pins on the negative voltage regulators "-12v and -5v" were putting off -18v and -3v, is that normal? does yours do this?
> > > 
> > > On Aug 2, 2012, at 8:24 PM, wesleyknick wrote:
> > > 
> > > > For anybody interested in this particular issue, that of strange characters showing up in the display at power-on and those same characters changing as keys are pressed (almost like a typewriter), I've determined the power supply to be the problem. I had initially suspected the power supply when I began looking into the issue however after checking all the output voltages I had found them all to be within limits and looked elsewhere. Looking elsewhere I had also suspected the RAM which included my swapping out U6, U7, and U8 and still had the same problem. Again suspecting the power supply and trying an alternate approach, I removed the power supply board from my other fully functional Matrix 6 and installed it into the problematic Matrix 6 and all issues were cleared. I then proceeded to upload the original factory presets with no issues. I'm not entirely sure what component is bad on the power supply, possibly the +5 or +12 voltage regulators but either way I've finally narrowed down what's causing the issue.
> > > > 
> > > > The bottom line, if you display starts displaying strange characters and gibberish, it's safe to say your power supply is showing inital symptons of failure. I'm going to strip the bad power supply board and check all the caps with an ESR tester and probably just go ahead and replace all the regulators with new and it should clear the problem.
> > > > 
> > > > Hope this helps anybody else with the same issue...
> > > > 
> > > > 
> > > > --- In oberheim@yahoogroups.com, "wesleyknick" <wesknick@> wrote:
> > > > >
> > > > > It does play with output though after loading the factory patches they don't sound correct when compared to my fully functional Matrix 6 in addition to the garbled display.  
> > > > > 
> > > > > I went ahead and swapped the processor boards in the two synths, something not without some risk of damaging the good processor board. Nevertheless, installing the good processor board in the originally faulty Matrix 6 resulted in a fully functional keyboard with a slightly hissy output. Installing the suspected faulty processor board in the fully functional Matrix 6 resulted in power on problems whereby the display wouldn't light up, strange output on several of the factory patches, and a few of the keys in various places on the keyboard were non-functional. With regard to the power on problems, I'd have to cycle the on-off switch two or three times to get the display to light up. With the bad processor board in the 'good' Matrix 6 synth however, I didn't get a garbled display full of characters, only the display wouldn't usually light up on the first attempt at power on. When the display did light up in was readable. I went ahead and reloaded the original factory patches with the bad processor board however they still didn't sound correct...
> > > > > 
> > > > > --- In oberheim@yahoogroups.com, carl hourigan <sloppy.hq@> wrote:
> > > > > >
> > > > > > I had the same problem for at least a year or so with my matrix 6. when it came to me half of the patches were normal the other half were the weird characters thing. the dude i got it from said he thought it was "some dead voice chips" i told him he was an idiot and to stick to playing guitars, then i bought it... (im dumb too i guess). one thing, mine sometimes would just be dead for a month then one day it would decide to power up and have crazy ass characters allover, or it would just power up fine to factory presets. after continuous tinkering for a year or so i have got it to power up every time into a hard reset/calibration mode, im not sure why it just jumps to calibration. In other words i cant save any patches i make unless i involve my librarian. Also i have no idea what i did to get it this far, because at this point ive tried every little possible thing to get it working right, voltages, battery, traces, wires, reseating, cleaning and psycho therapy...
> > > > > > anyway its interesting to hear im not alone, hope you guys figure this out, i would love to get mine working perfectly.
> > > > > > 
> > > > > > 
> > > > > > > Does it play OK, and you can still adjust parameters etc, only the display is problematic?
> > > > > > > 
> > > > > > > From: wesleyknick <wesknick@>
> > > > > > > To: oberheim@yahoogroups.com 
> > > > > > > Sent: Wednesday, 18 July 2012, 22:06
> > > > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > > > > 
> > > > > > > 
> > > > > > > I just joined the group yesterday. If you can point me to the previous discussion I'd appreciate it. The problem is it sometimes powers on without a display, other times it's limited to 7 or so characters and other times the whole diplay fills up with random characters than change when I press the keys. It seems too erratic to be a self-test mode.
> > > > > > > 
> > > > > > > --- In oberheim@yahoogroups.com, Peter Mörck <peter@> wrote:
> > > > > > > >
> > > > > > > > This sounds familiar...
> > > > > > > > Isn't this part of the display CPU self-test mode functionality, or 
> > > > > > > > something like that?
> > > > > > > > Wasn't something like this discussed on this list about a month ago or so?
> > > > > > > > 
> > > > > > > > BR,
> > > > > > > > Peter
> > > > > > > > 
> > > > > > > > ----- Original Message ----- 
> > > > > > > > From: wesleyknick
> > > > > > > > To: oberheim@yahoogroups.com
> > > > > > > > Sent: Wednesday, July 18, 2012 10:47 PM
> > > > > > > > Subject: [oberheim] Re: Oberheim Matrix 6, Dead?
> > > > > > > > 
> > > > > > > > 
> > > > > > > > Most of the time it just powers on with a string of characters in the 
> > > > > > > > display and pressing the keys simply enters new characters in the display as 
> > > > > > > > though I'm typing them in.
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