Crumar Musical Instruments User Group.

Hi! the other i cleaned my DS-2, before cleaning it. one oscillator wouldn't 
work, then after spraying everything with a contact cleaner. when i plugged 
it in, the oscillator worked! but after a minute it didn't again. what you i 
think i should do next?

diego



http://www.monsterbot.org

http://www.monopond.150m.com





>From: Steve Ridley <spr@...>
>Reply-To: crumar@yahoogroups.com
>To: crumar@yahoogroups.com
>Subject: RE: [crumar] Re: Bit One Repair
>Date: Tue, 15 Aug 2006 14:36:17 +0200 (CEST)
>
>
> > Yeah, I triple checked. I'm supposed to be using the case ground,
> > right? -17v Of course this changes if I unplug the cables that
> > attach the PSU to the rest of the keyboard.
>
>I can't remember if the case is 0v or not - don't bet on it.  I would
>expect the outside of the output jack to be at 0v, but look for the
>0v connections on the power supply connector to be sure (JA4-5, JB 2-4,
>J0 2-4).  BTW, the same PSU appears to be used in both versions.
>
> > Would you suggest that PSU is damaged, or is something attached to the
> > PSU causing this problem?
>
>It could be either.  You could have a faulty 12v regulator (note, the
>pinouts of the +12v and -12v regulators are not the same) then one of
>the rails might go quite high (like 17v).  OTOH, if the 5v rail got
>shorted to chassis, then the -12v might measure -17v to chassos and the
>+12v would measure 7v.
>
>So, unplug the power connectors and measure the +12v and -12v on the
>PSU board, using the PSU 0v as ground.
>
>If the PSU measures OK, switch off and reconnect one connector at a
>time, switch on and see which board is causing the problem.
>
> > Strangely enough, the keyboard partially function, can load sounds
> > from tape, play sounds, etc...
>
>Most of the control sysem of the synth runs on a +5v supply, which is
>clearly working fine.
>
>And PLEASE WATCH OUT FOR THE MAINS!
>
>
>Steve
>
>
>
>
>
>Yahoo! Groups Links
>
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>

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