Vintage Synth Repair

Hi,
I just joined. I found three nonworking synths and bought them for 
$30 each. A Prophet 10, Korg Trident mk II, and Roland Super JX 10.
1)The Prophet has some regulators in wrong. The 12v and 5V were 
backwards but the 12V should have been fixed voltage and had a 
varible regulator instead of fixed Vreg without feedback resistors. 
Hopefully that fixes that. There may have been some big voltage on 
the 5V circuit. I'm a little concerned because that reg open loop may 
have been 37v. It lit up though while wrong just no sound.
2)The Korg had a memory battery leak on the board and fried some 
traces. So PCB repair and new battery may fix that. I like my odds on 
this one. It lit up too but no sound.
3) The Roland has good Power supply but nothing lights up. The whole 
top LCD or LED plus all the buttons are out. I could appreciate 
advice or if anyone has a schematic would help. If I get one synth 
working I made a good purchase. I'm optimistic on the first two. They 
light up and look like they want to work.

Thanks,
Frank

I'll talk about my Hammond H-100 problems later.

--- In vintagesynthrepair@yahoogroups.com, "fsimon100" <fsimon001@...>
wrote:
>
> Hi,
> I just joined. I found three nonworking synths and bought them for 
> $30 each. A Prophet 10, Korg Trident mk II, and Roland Super JX 10.
> 1)The Prophet has some regulators in wrong. The 12v and 5V were 
> backwards but the 12V should have been fixed voltage and had a 
> varible regulator instead of fixed Vreg without feedback resistors. 
> Hopefully that fixes that. There may have been some big voltage on 
> the 5V circuit. I'm a little concerned because that reg open loop may 
> have been 37v. It lit up though while wrong just no sound.
> 2)The Korg had a memory battery leak on the board and fried some 
> traces. So PCB repair and new battery may fix that. I like my odds on 
> this one. It lit up too but no sound.
> 3) The Roland has good Power supply but nothing lights up. The whole 
> top LCD or LED plus all the buttons are out. I could appreciate 
> advice or if anyone has a schematic would help. If I get one synth 
> working I made a good purchase. I'm optimistic on the first two. They 
> light up and look like they want to work.
> 
> Thanks,
> Frank
> 
> I'll talk about my Hammond H-100 problems later.
>
I have Hammond H-100 parts

On Tuesday 01 April 2008 08:04, Scott wrote:
> --- In vintagesynthrepair@yahoogroups.com, "fsimon100" <fsimon001@...>
>
> wrote:
> > Hi,
> > I just joined. I found three nonworking synths and bought them for
> > $30 each. A Prophet 10, Korg Trident mk II, and Roland Super JX 10.
> > 1)The Prophet has some regulators in wrong. The 12v and 5V were
> > backwards but the 12V should have been fixed voltage and had a
> > varible regulator instead of fixed Vreg without feedback resistors.
> > Hopefully that fixes that. There may have been some big voltage on
> > the 5V circuit. I'm a little concerned because that reg open loop may
> > have been 37v. It lit up though while wrong just no sound.
> > 2)The Korg had a memory battery leak on the board and fried some
> > traces. So PCB repair and new battery may fix that. I like my odds on
> > this one. It lit up too but no sound.
> > 3) The Roland has good Power supply but nothing lights up. The whole
> > top LCD or LED plus all the buttons are out. I could appreciate
> > advice or if anyone has a schematic would help. If I get one synth
> > working I made a good purchase. I'm optimistic on the first two. They
> > light up and look like they want to work.
> >
> > Thanks,
> > Frank
> >
> > I'll talk about my Hammond H-100 problems later.
>
> I have Hammond H-100 parts

I have a couple or three loose-leaf binders full of Hammond stuff I haven't 
even looked at yet.  What kinda parts do you have?  It's been so long since I 
did much work on Organs (probably stopped around 1985 or so) I don't even 
remember the H-100...

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James 
M Dakin

Are you sure this not an April Fool's hoax ?! ;)

30$ each ?? for a P10 ? Trident ? JX10 ?

Sounds tooooo good to be true !

:))



--- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason"
<rtellason@...> wrote:
>
> On Tuesday 01 April 2008 08:04, Scott wrote:
> > --- In vintagesynthrepair@yahoogroups.com, "fsimon100" <fsimon001@>
> >
> > wrote:
> > > Hi,
> > > I just joined. I found three nonworking synths and bought them for
> > > $30 each. A Prophet 10, Korg Trident mk II, and Roland Super JX 10.
> > > 1)The Prophet has some regulators in wrong. The 12v and 5V were
> > > backwards but the 12V should have been fixed voltage and had a
> > > varible regulator instead of fixed Vreg without feedback resistors.
> > > Hopefully that fixes that. There may have been some big voltage on
> > > the 5V circuit. I'm a little concerned because that reg open
loop may
> > > have been 37v. It lit up though while wrong just no sound.
> > > 2)The Korg had a memory battery leak on the board and fried some
> > > traces. So PCB repair and new battery may fix that. I like my
odds on
> > > this one. It lit up too but no sound.
> > > 3) The Roland has good Power supply but nothing lights up. The whole
> > > top LCD or LED plus all the buttons are out. I could appreciate
> > > advice or if anyone has a schematic would help. If I get one synth
> > > working I made a good purchase. I'm optimistic on the first two.
They
> > > light up and look like they want to work.
> > >
> > > Thanks,
> > > Frank
> > >
> > > I'll talk about my Hammond H-100 problems later.
> >
> > I have Hammond H-100 parts
> 
> I have a couple or three loose-leaf binders full of Hammond stuff I
haven't 
> even looked at yet.  What kinda parts do you have?  It's been so
long since I 
> did much work on Organs (probably stopped around 1985 or so) I don't
even 
> remember the H-100...
> 
> -- 
> Member of the toughest, meanest, deadliest, most unrelenting -- and
> ablest -- form of life in this section of space,  a critter that can
> be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet
Masters"
> -
> Information is more dangerous than cannon to a society ruled by
lies. --James 
> M Dakin
>

Well I've nearly brought my Arp Quadra back from the
dead since I found a source of 8243's in the UK. Still
got a couple of buttons not working though...sigh..oh
well hehe.

Anyway now I've moved on to my Roland VP-330.
Basically the vocoder doesn't work. Plug a mic in
press the keys..nothing..silence. You can hear the mic
direct sound if you turn the fader up. I tried feeding
another synth into the external synth in..still
nothing. The strings and the human voice sounds work
perfectly.

Any advice to help me get going?..I've just started
reading the service manual..

Once this is done...I might even look at my very sick SK-20.


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--- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason" 
<rtellason@...> wrote:
>
> On Tuesday 01 April 2008 08:04, Scott wrote:
> > --- In vintagesynthrepair@yahoogroups.com, "fsimon100" 
<fsimon001@>
> >
> > wrote:
> > > Hi,
> > > I just joined. I found three nonworking synths and bought them 
for
> > > $30 each. A Prophet 10, Korg Trident mk II, and Roland Super JX 
10.
> > > 1)The Prophet has some regulators in wrong. The 12v and 5V were
> > > backwards but the 12V should have been fixed voltage and had a
> > > varible regulator instead of fixed Vreg without feedback 
resistors.
> > > Hopefully that fixes that. There may have been some big voltage 
on
> > > the 5V circuit. I'm a little concerned because that reg open 
loop may
> > > have been 37v. It lit up though while wrong just no sound.
> > > 2)The Korg had a memory battery leak on the board and fried some
> > > traces. So PCB repair and new battery may fix that. I like my 
odds on
> > > this one. It lit up too but no sound.
> > > 3) The Roland has good Power supply but nothing lights up. The 
whole
> > > top LCD or LED plus all the buttons are out. I could appreciate
> > > advice or if anyone has a schematic would help. If I get one 
synth
> > > working I made a good purchase. I'm optimistic on the first 
two. They
> > > light up and look like they want to work.
> > >
> > > Thanks,
> > > Frank
> > >
> > > I'll talk about my Hammond H-100 problems later.
> >
> > I have Hammond H-100 parts
> 
> I have a couple or three loose-leaf binders full of Hammond stuff I 
haven't 
> even looked at yet.  What kinda parts do you have?  It's been so 
long since I 
> did much work on Organs (probably stopped around 1985 or so) I 
don't even 
> remember the H-100...
> 
> -- 
> Member of the toughest, meanest, deadliest, most unrelenting -- and
> ablest -- form of life in this section of space,  a critter that can
> be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet 
Masters"
> -
> Information is more dangerous than cannon to a society ruled by 
lies. --James 
> M Dakin
>
**********************************************************************
H-100
My preset keys won't stay engauged. How do you disassemble to get 
underneath keys. Also I have low volume if I hold them down manually. 
I know tube outputs are good but not sure where the low signal is.

Hi thanks, I got it fixed a while ago, It was a dead
TL082 op-amp(IC2)located in the vocoder board known as
ETH16..mine has the push switches by the way not the
rockers..

Phil.




--- akira honda <oxygeno1313@...> wrote:

> hi,
>    
>   i had a similar problem long time ago, i own 2
> VP-330 and both had the same problem, i replaced the
> op amps from each filter, also check the rocker
> swtiches if they are making good contact.
>    
>   hope this works for you.
>   
> 
> Philip <eggwheatis@...> wrote:
>           Well I've nearly brought my Arp Quadra
> back from the
> dead since I found a source of 8243's in the UK.
> Still
> got a couple of buttons not working
> though...sigh..oh
> well hehe.
> 
> Anyway now I've moved on to my Roland VP-330.
> Basically the vocoder doesn't work. Plug a mic in
> press the keys..nothing..silence. You can hear the
> mic
> direct sound if you turn the fader up. I tried
> feeding
> another synth into the external synth in..still
> nothing. The strings and the human voice sounds work
> perfectly.
> 
> Any advice to help me get going?..I've just started
> reading the service manual..
> 
> Once this is done...I might even look at my very
> sick SK-20.
> 
>
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> A Smarter Inbox
> http://uk.docs.yahoo.com/nowyoucan.html
> 
> 
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> 
>        
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