OBERHEIM SYNTH

the -3v sounds a bit low- i mean, low for normal operation.

----- Original Message ----- 
From: "carl hourigan" <sloppy.hq@...>
To: <oberheim@yahoogroups.com>
Sent: Friday, August 03, 2012 3:22 AM
Subject: Re: [oberheim] Re: Oberheim Matrix 6, Dead?


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 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.
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> >
>
>