Patches and discussion for Ensoniq VFX family

bought the battery off ebay, reads 2.97 volts.  metered the mainboard, 
power is getting to where it should. the display lights are dim, the 
buttons change presets but what tiny little bit of sound that comes 
out is the same no matter what.   it sounds like a sawtooth, doesn't 
change pitch no matter which key i hit.  the sequencer will not stay 
loaded. i read the posts and saw somewhat similar problems. do you 
think it is the main power supply or a cap that regulates it?  has 
anyone dealt with www.thesoniq.com for repairs? anyone have a 
schematic source?
thanks so much, i am glad to be a part of this group!!

This sounds similar to a problem I had except, all I got was the
"battery low" warning, no sounds.  The battery voltage is compared to a
voltage from the PSU.  So if this becomes unstable. 

In my case a diode had blown on the bridge rectifier.  I believe there
are 6 and if ones gone it might be an idea to change all 6.

 

I hope this helps.

 

John

-----Original Message-----
From: Ensoniq-VFX-SD@yahoogroups.com
[mailto:Ensoniq-VFX-SD@yahoogroups.com] On Behalf Of
markbreton@...
Sent: 16 January 2009 22:55
To: Ensoniq-VFX-SD@yahoogroups.com
Subject: [Ensoniq-VFX-SD] sd1 battery died, changed, still get low
voltage message

 

bought the battery off ebay, reads 2.97 volts. metered the mainboard, 
power is getting to where it should. the display lights are dim, the 
buttons change presets but what tiny little bit of sound that comes 
out is the same no matter what. it sounds like a sawtooth, doesn't 
change pitch no matter which key i hit. the sequencer will not stay 
loaded. i read the posts and saw somewhat similar problems. do you 
think it is the main power supply or a cap that regulates it? has 
anyone dealt with www.thesoniq.com for repairs? anyone have a 
schematic source?
thanks so much, i am glad to be a part of this group!!

On Sat, 2009-01-17 at 01:13 +0000, John wrote:
> This sounds similar to a problem I had except, all I got was the
> \u201cbattery low\u201d warning, no sounds.  The battery voltage is compared to
> a voltage from the PSU.  So if this becomes unstable\u2026 
> 
> In my case a diode had blown on the bridge rectifier.  I believe there
> are 6 and if ones gone it might be an idea to change all 6.

I'd go along with this.  People go on about smoothing caps failing, but
I've had far more trouble from rectifier diodes failing.  If they fail
short-circuit then you may find problems with the smoothing caps too.

Get a big bag of power diodes, and replace the lot.  I use the 800V 8A
diodes which are physically very large and may need the holes in the
board drilled out a little, whatever I'm replacing them in.  Sometimes
if I'm repairing a power supply with a large 5V draw I'll use even
higher current diodes.  They'll never ever fail again.  Ever.

Gordon

--- In Ensoniq-VFX-SD@yahoogroups.com, "John" <john.boyle03@...> wrote:
>
> This sounds similar to a problem I had except, all I got was the
> "battery low" warning, no sounds.  The battery voltage is compared to 
a
> voltage from the PSU.  So if this becomes unstable. 
> 
> In my case a diode had blown on the bridge rectifier.  I believe there
> are 6 and if ones gone it might be an idea to change all 6.
> 
>  
> 
> I hope this helps.
> 
>  
> 
> John
> 

thanks a bunch for the feedback.  i had been so focused on the 
mainboard and battery that i, king knuclehead, forgot to check the 
FUSES!! i have a blown 1.5v 250 amp fuse blown.  i will replace that 
and see what i get, and if i need to i will pursue your suggestion.

as per a previous post, i found a bad fuse, changed the fuse, powered 
up, and didn't get the low voltage message. Plugged in the 
headphones, same crappy sound.  powered down, powered up, got the low 
voltage message; the fuse had blown.  so i definitely have a power 
problem. i don't have a schematic, and am a little to ignorant to 
look at the diodes and see what is what.  i am thinking about sending 
it out to TheSoniq and having him run it all down.

--- In Ensoniq-VFX-SD@yahoogroups.com, "John" <john.boyle03@...> 
wrote:
>
> This sounds similar to a problem I had except, all I got was the
> "battery low" warning, no sounds.  The battery voltage is compared 
to a
> voltage from the PSU.  So if this becomes unstable. 
> 
> In my case a diode had blown on the bridge rectifier.  I believe 
there
> are 6 and if ones gone it might be an idea to change all 6.
> 
>  
> 
> I hope this helps.
> 
>  
> 
> John
> 
> -----Original Message-----
> From: Ensoniq-VFX-SD@yahoogroups.com
> [mailto:Ensoniq-VFX-SD@yahoogroups.com] On Behalf Of
> markbreton@...
> Sent: 16 January 2009 22:55
> To: Ensoniq-VFX-SD@yahoogroups.com
> Subject: [Ensoniq-VFX-SD] sd1 battery died, changed, still get low
> voltage message
> 
>  
> 
> bought the battery off ebay, reads 2.97 volts. metered the 
mainboard, 
> power is getting to where it should. the display lights are dim, 
the 

> buttons change presets but what tiny little bit of sound that comes 
> out is the same no matter what. it sounds like a sawtooth, doesn't 
> change pitch no matter which key i hit. the sequencer will not stay 
> loaded. i read the posts and saw somewhat similar problems. do you 
> think it is the main power supply or a cap that regulates it? has 
> anyone dealt with www.thesoniq.com for repairs? anyone have a 
> schematic source?
> thanks so much, i am glad to be a part of this group!!
>

Thanks.  In this instance, actually, I got lucky in that my engineer 
friend was able to troubleshoot the problem all the way back to the 
transformer. the fuse link that is shorting is getting too much 
amperage from the transformer. i put a 2amp fuse in it and for a 
couple of seconds it sounded glorious!! but then the with the wrong 
power level getting through it started sounding bad again.  So i am 
going to order a new transformer from thesoniq for it.  i know i am 
going to keep track of all of these troubleshooting tips for the 
future.  it's like trying to keep an old hoopty running.  you love 
it, but it requires a lot of tenderness! 


--- In Ensoniq-VFX-SD@yahoogroups.com, Leo Magpoc <leomagpoc@...> 
wrote:
>
> Try unplugging all cables and boards to the power supply then 
power on and see if the fuse still blows if it does it is something 
on the power supply board if it does not, plug in cables one at a 
time until it blows again the one you plug in that causes it to blow 
is where the problem is, I got my VFX at a garage sale and it wasn't 
working and being an electronic tech i used this aproach to fix it. 
It turned out to be the floppy drive cable was pinched and grounding 
out against some metal.
> 
> Leo
> 
> --- On Sun, 1/18/09, markbreton@... <markbreton@...> wrote:
> From: markbreton@... <markbreton@...>
> Subject: [Ensoniq-VFX-SD] Re: sd1 battery died, changed, still get 
low voltage message
> To: Ensoniq-VFX-SD@yahoogroups.com
> Date: Sunday, January 18, 2009, 1:22 PM
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
>     
>             as per a previous post, i found a bad fuse, changed 
the fuse, powered 
> 
> up, and didn't get the low voltage message. Plugged in the 
> 
> headphones, same crappy sound.  powered down, powered up, got the 
low 
> 
> voltage message; the fuse had blown.  so i definitely have a power 
> 
> problem. i don't have a schematic, and am a little to ignorant to 
> 
> look at the diodes and see what is what.  i am thinking about 
sending 
> 
> it out to TheSoniq and having him run it all down.
> 
> 
> 
> --- In Ensoniq-VFX- SD@yahoogroups. com, "John" 
<john.boyle03@ ...> 
> 
> wrote:
> 
> >
> 
> > This sounds similar to a problem I had except, all I got was the
> 
> > "battery low" warning, no sounds.  The battery voltage is 
compared 
> 
> to a
> 
> > voltage from the PSU.  So if this becomes unstable. 
> 
> > 
> 
> > In my case a diode had blown on the bridge rectifier.  I believe 
> 
> there
> 
> > are 6 and if ones gone it might be an idea to change all 6.
> 
> > 
> 
> >  
> 
> > 
> 
> > I hope this helps.
> 
> > 
> 
> >  
> 
> > 
> 
> > John
> 
> > 
> 
> > -----Original Message-----
> 
> > From: Ensoniq-VFX- SD@yahoogroups. com
> 
> > [mailto:Ensoniq-VFX- SD@yahoogroups. com] On Behalf Of
> 
> > markbreton@ ..
> 
> > Sent: 16 January 2009 22:55
> 
> > To: Ensoniq-VFX- SD@yahoogroups. com
> 
> > Subject: [Ensoniq-VFX- SD] sd1 battery died, changed, still get 
low
> 
> > voltage message
> 
> > 
> 
> >  
> 
> > 
> 
> > bought the battery off ebay, reads 2.97 volts. metered the 
> 
> mainboard, 
> 
> > power is getting to where it should. the display lights are dim, 
> 
> the 
> 
> > buttons change presets but what tiny little bit of sound that 
comes 
> 
> > out is the same no matter what. it sounds like a sawtooth, 
doesn't 
> 
> > change pitch no matter which key i hit. the sequencer will not 
stay 
> 
> > loaded. i read the posts and saw somewhat similar problems. do 
you 
> 
> > think it is the main power supply or a cap that regulates it? 
has 

> 
> > anyone dealt with www.thesoniq. com for repairs? anyone have a 
> 
> > schematic source?
> 
> > thanks so much, i am glad to be a part of this group!!
> 
> >
>

On Thu, 2009-01-22 at 15:23 +0000, markbreton@... wrote:
> Thanks.  In this instance, actually, I got lucky in that my engineer 
> friend was able to troubleshoot the problem all the way back to the 
> transformer. the fuse link that is shorting is getting too much 
> amperage from the transformer. i put a 2amp fuse in it and for a 
> couple of seconds it sounded glorious!! but then the with the wrong 
> power level getting through it started sounding bad again.  So i am 
> going to order a new transformer from thesoniq for it.  i know i am 
> going to keep track of all of these troubleshooting tips for the 
> future.  it's like trying to keep an old hoopty running.  you love 
> it, but it requires a lot of tenderness! 
> 

No, wait, don't - I've never ever heard of a transformer failing in a
way that would cause that.  Not saying it can't happen, but I've never
heard of *that*...

It's far more likely to be one of the diodes in the rectifier.  You need
to check them, and if one has gone change the whole lot.

Gordon

ok, that i will do.   i can't get a hold of the soniq, i have emailed
and called to arrange to just send him the keyboard but have not heard
back, and he doesn't have an answering machine.  interesting chap.  how
do i check a diode?
--- In Ensoniq-VFX-SD@yahoogroups.com, Gordon JC Pearce MM3YEQ
<gordon@...> wrote:
>
> On Thu, 2009-01-22 at 15:23 +0000, markbreton@... wrote:
> > Thanks. In this instance, actually, I got lucky in that my engineer
> > friend was able to troubleshoot the problem all the way back to the
> > transformer. the fuse link that is shorting is getting too much
> > amperage from the transformer. i put a 2amp fuse in it and for a
> > couple of seconds it sounded glorious!! but then the with the wrong
> > power level getting through it started sounding bad again. So i am
> > going to order a new transformer from thesoniq for it. i know i am
> > going to keep track of all of these troubleshooting tips for the
> > future. it's like trying to keep an old hoopty running. you love
> > it, but it requires a lot of tenderness!
> >
>
> No, wait, don't - I've never ever heard of a transformer failing in a
> way that would cause that. Not saying it can't happen, but I've never
> heard of *that*...
>
> It's far more likely to be one of the diodes in the rectifier. You
need

> to check them, and if one has gone change the whole lot.
>
> Gordon
>

On Fri, 2009-01-30 at 21:48 +0000, markbreton@... wrote:
> ok, that i will do.   i can't get a hold of the soniq, i have emailed
> and called to arrange to just send him the keyboard but have not heard
> back, and he doesn't have an answering machine.  interesting chap.  how
> do i check a diode?

Okay, you're going to either need to learn a bit about electronics, or
find someone to help you ;-)

On the power supply board there are sets of diodes arranged as a "bridge
rectifier" which is essentially a way of turning the AC power into a
rough approximation of DC, which is then smoothed by the capacitors and
regulated by the regulators.

There are a number of things that can go wrong.  From my own experience,
I've found that the rectifier diodes fail quite often on older synths,
usually short-circuit.  They're supposed to only pass current one way,
but when they blow they start to pass current *both* ways - not a good
state of affairs, and one that will definitely blow fuses in the VFX
power supply (the VFX and VFX-SD power supplies look the same.  They
might be the same as EPS ones too, I need to compare side-by-side.  My
VFX power supply has a floppy disk power connector).

Basically to test them, you need to remove them from the board (making
sure you know how they go back in), and check that they only pass
current one way.  If they don't pass any current either way, or pass
current both ways, they're stuffed and you need to replace all four (no
point just doing one - another will fail immediately when you put the
power back on, most of the time).  It's not hard, but you *will* need a
few specialised tools and a bit of skill with soldering.  Find your
friendly neighbourhood electronics geek and bring your synth round with
some beer or other socially acceptable bribe.

I usually replace the diodes in synth power supplies with ones rated at
10A at 800V.  They don't need to be that big, but it means they will
never ever fail again.

Gordon

Yes, I agree with Gordon.  When mines initially blew I had to do a quick
fix and managed to get a diode from an old car alarm.  The synth worked
fine for a few months and then failed with the "batter Low" warning
again.  Another diode had gone and this time it had taken out a
regulator.  I replaced all 6 diodes and the regulator and my synth has
been going for years since.

 

John

-----Original Message-----
From: Ensoniq-VFX-SD@yahoogroups.com
[mailto:Ensoniq-VFX-SD@yahoogroups.com] On Behalf Of Gordon JC Pearce
MM3YEQ
Sent: 31 January 2009 01:06
To: Ensoniq-VFX-SD@yahoogroups.com
Subject: Re: [Ensoniq-VFX-SD] Re: sd1 battery died, changed, still get
lowvoltage message

 

On Fri, 2009-01-30 at 21:48 +0000, markbreton@ymail.
<mailto:markbreton%40ymail.com> com wrote:
> ok, that i will do. i can't get a hold of the soniq, i have emailed
> and called to arrange to just send him the keyboard but have not heard
> back, and he doesn't have an answering machine. interesting chap. how
> do i check a diode?

Okay, you're going to either need to learn a bit about electronics, or
find someone to help you ;-)

On the power supply board there are sets of diodes arranged as a "bridge
rectifier" which is essentially a way of turning the AC power into a
rough approximation of DC, which is then smoothed by the capacitors and
regulated by the regulators.

There are a number of things that can go wrong. From my own experience,
I've found that the rectifier diodes fail quite often on older synths,
usually short-circuit. They're supposed to only pass current one way,
but when they blow they start to pass current *both* ways - not a good
state of affairs, and one that will definitely blow fuses in the VFX
power supply (the VFX and VFX-SD power supplies look the same. They
might be the same as EPS ones too, I need to compare side-by-side. My
VFX power supply has a floppy disk power connector).

Basically to test them, you need to remove them from the board (making
sure you know how they go back in), and check that they only pass
current one way. If they don't pass any current either way, or pass
current both ways, they're stuffed and you need to replace all four (no
point just doing one - another will fail immediately when you put the
power back on, most of the time). It's not hard, but you *will* need a
few specialised tools and a bit of skill with soldering. Find your
friendly neighbourhood electronics geek and bring your synth round with
some beer or other socially acceptable bribe.

I usually replace the diodes in synth power supplies with ones rated at
10A at 800V. They don't need to be that big, but it means they will
never ever fail again.

Gordon