[sdiy] Minimoog PSU problem

[Matti Kari]

Hello,

My Mini (#10402) has developed a PSU problem. First it was intermittent, 
but now it seems to be here to stay. The overload light stays on all the 
time.

It may be a contact problem, since sometimes the old "hard punch to the 
bottom" trick fixes the problem, but I've replaced and cleaned all the 
card connectors without success.

When the problem is occurring, there's both positive and negative 
voltages (~ +/- 20 volts) coming in to the main regulator transistors 
(Q1 and Q20 on PSU board), but the output voltages are not correct. I 
have checked & cleaned the adjust pots, they are ok.

While I have quite a lot of experience building tube amplifiers and 
such, I have to admit that I'm really an amateur what comes to 
transistor circuits.

Thanks a lot for any ideas,

matti

-- 
Matti Kari
maza at maza.fi
040 838 6607