Vintage Synth Repair

Most, if not all Roland schematics are available in PDF
from...surprise, surprise....Roland! Phone or email them.

He he.. you'll get a lot more than your money back right now..as
is..so I wouldn't be too worried.

>>Roland JX10 is total dead. I think power supply was good. Lower
priority. This one I don't have a schematic. Do you have one?


--- In vintagesynthrepair@yahoogroups.com, "Frank Simon"
<fsimon001@...> wrote:
>
> Hi Steve,
> I hope everyone doesn't attack you at once. I had  a crazy
experience where I bought a Prophet 10, Korg Trident Mk II, and Roland
JX 10 all for $30 each non working. I am an RF engineer and novice
musician/Audio repairman. I know linear more than digital but I am
going to throw out some questions since you offered. 
> 1)My Trident I fixed due to NiCad battery meltdown destroying traces
but I repaired the PC board(with wire) and all works great Strings,
Brass, FLANGER!!!, but the Synth section makes occasional odd noises
sounds like processing. Any trouble shooting advice would be appreciated.
> 2) The P10 had no sound, lit up, I found a 5V regulator pulled down.
Found the bad IC(burned my finger). Then like a dumb a## I was
checking -5V reg T0-220 on a voice board,slipped shorted output to
input and took out 4 CEM3310. OUCH!! Still don't know why due to
internal Zener in CEM3310. I want to continue toubleshooting but don't
want to buy pricey chips until my confidence is up. Can I put the
board in without 4 of the 10 CEM3310 and continue. I'm sure no sound
but -5v reg will be up. Any advice appreciated.
> 3) Roland JX10 is total dead. I think power supply was good. Lower
priority. This one I don't have a schematic. Do you have one?
> 4) Finally my Hammond H-112 had low volume and I found unplugging
the Reverb tank it came back full volume. I think the reverb is ok. Do
you think it could be a tube driver? Sounds odd that it would shut the
amps down.
> 
> Sorry for the overload. I'm excited about these synths. If I fix one
I got more than my money back. The Korg is very close. I will cry if I
can't fix the P10.
> Thanks,
> Frank
>  
> 
>   ----- Original Message ----- 
>   From: thirteentech 
>   To: vintagesynthrepair@yahoogroups.com 
>   Sent: Tuesday, April 15, 2008 7:54 AM
>   Subject: [vintagesynthrepair] Hi from a new member.
> 
> 
>   Just wanted to introduce myself... I am a synthesizer service tech
from Sydney, Australia. I 
>   have been fixing synths since 1982, as well as a lot of touring as
a keyboard tech. Currently I 
>   have around 22 vintage machines that I play and use for recording,
and have been a warranty 
>   tech in Australia over the years for PPG, Kurzweil E-mu and
Sequential. Hope I can help out a 
>   little on the forum, and learn some new things too :-)
> 
>   Steve Jones.
>