[sdiy] sem repair

[greg montalbano]

Sounds very much like they shorted something out (that was connected to 
the  power rail) while they were poking around in there -- this could 
easily cause partial or complete failure of ICs, caps, diodes, etc.

Time to get out the schematic for the VCO board & go through it, component 
by component.

~GMM

At 11:42 PM 7/19/02 +0200, Mark wrote:
>Hi,
>
>I am fixing an Oberheim SEM and need some guidance. The owner tried to 
>trim the V/Oct response and sharted something that caused the power supply 
>to blow up. I have replaced the 723 and got the power working again, with 
>the VCO's cut off from the power. However, when they are connected, the 
>positive rail drops from 15 volts down to 8 volts. I can't check what's 
>wrong with the VCO's if the power isn't working? What could cause this? I 
>have never seen a dead OP amp mess with the power rail. could it? Anyone 
>know this problem?
>
>please help!
>
>mark
>