Hello iscrites

first of all before you switch on the synth: unplug the five connectors
CN 31 - CN 35 from the powersupply before you start working again. Do
not reconnect them until den power supply works correctly. After the
powersupply has been repaired. Connect them one by one and measure the
voltages after adding each connector.


To the problem:

> - 26.5v out of the transformer (on KLM376/ cn37 connector)

26.5V AC between the two hot transformer outputs looks reasonable.

> - +37v and -37v from the 1S1885 diodes to the inputs of the M5230L

(pin 7 and 4)
Did you measure this against ground (pin1 of M3250L) or did you measure
7 against 4 If 7 against 4, then it sounds reasonable. What does read 7
against 1 and 4 against 1

What is broken then I cannot judge And often it does not make sense to
repair such an old powersupply.

You may use simply a completely different powersupply, which provides
+15,-15 and +5 Volts. You may use also a switching powersupply block
like a Mean Well or a Traco. I prefer Tracos as they are nearly
undestroyable.

Florian





Am 23.10.2012 14:45, schrieb iscrites:

> What is sure is that the 376 board is damaged because I don't have the +15v -15V or 5V.
> So far the reading I got are (schematic is here: http://fa.utfs.org/diy/korg_monopoly/mp_10_klm-376_powersupply_klm-357_vcoheater_schemo.gif) :
> - 26.5v out of the transformer (on KLM376/ cn37 connector)
> - +37v and -37v from the 1S1885 diodes to the inputs of the M5230L (pin 7 and 4)
>
> I have no output reading from the M5230L. So does it means this one is fried or can it be some other componant that makes that I have no output from the M5230L
> I'm not a real technician, I don't know much but if someone can explain I can track the problem.
>
> Hope someone can help.
> Thanx in advance
>

--
http://fa.utfs.org/