My +12VDC is measuring around +5VDC (don't be confused by the coincidence that it is around 5V).

Here is what I've measured:
AC input voltage (pins 10/11) is supposed to be 18VAC. I measured about 20VAC.
I also measured the BR using the diode setting on my DMM, and all good.
Voltage across C1, -12VDC, as it should be.
Voltage across C11-C14, +5VDC. It should be +12VDC.
Capacitance across C1, 1000uf, as it should be.
Capacitance acress C11-C14, 19000uf, as it should be.
AC voltage across C11-C14, 0VAC, as it should be.
Resistance across C1, 6M ohm - I suspect that's correct.
Resistance across C11-C14, 6M ohm - I suspect that's correct.

I measured the capacitance and resistance with power off.
I measured the voltage with power supplied, obviously. I removed all connectors, so there would be no load.

I am a bit confused on how this can produce the wrong voltage, given what I have measured.
This is a REALLY simple circuit for

IMG_2547 (resized).jpg

Input to the BR is 20VAC (schematic indicates it should be 18VAC - but 20 is close enough).

Yes I have -12VDC at C1 (my green text on the schematic got truncated to -12VD).

Fuses are good.

Yep. I think that's it. I DID test the BR with the diode setting. But it makes sense with the info I have. I will test again. I have extra BR. So I can swap it out.

Thx.

BTW, it was pointed out to me that since the circuit uses pin 12 (the transformer center tap) as ground, this is basically two half wave rectified circuits: one for -12VDC, the other side for +12VDC. I think one of the four diodes in the BR is bad.

Frankenstein is running again.

I verified the BR did check out according to the diode setting on my DMM (all 4 diodes). But, as we suspected, one of those diodes was faulty, leaving with only around 5VDC (where I should have had 12VDC), while providing the -12VDC.

I did not. It is hard to do with the board installed into the backbox. I could have powered it unmounted; but I did not.

I did, however, double check the runs.

Thx again.