Counterpoint SA-100 MOSFETs Source?

It seems like something's wrong with the Vcc to the 555 timer. It's about 3.4 volts from Vcc to ground and it's all 120Hz ripple. I'm trying to find out where it's sourcing that power from. It's not on the schematic. Tried removing the PCB today and some of the bias transistor wires broke off from the process. I've replaced every electrolytic cap on the board. It seems like it's getting power from the filament circuit as Vcc pin 8 traces to one of the big capacitors on the board.
The other thing that's troubling is that the amplifier is drawing 175W from the line with no MOSFETs installed and the transformer heats up rather quickly. As in warm to the touch after 2 minutes running. I'm starting to be concerned that the winding for the filament circuit may be damaged from the event that lead up to the caps exploding when the customer last used it.
The physical layout, lack of plug in connectors and no access to solder side of PCB make troubleshooting very tedious and slow.
 
The gate timer is powered from the unregulated heater supply. The wrinkle is that the positive side is connected to ground to it is a nominal -6V supply. Here is snippet from the schematic to explain.

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If you are lucky, the bridge rectifier BR1 has died. If so, replace it with a chassis mount part bolted to the chassis floor in front of the PCB and then wire it to the plated-though holes that the original rectifier was fitted to.
If you are unlucky, then you have a dead transformer...
 

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You could rewind the transformer which is unlikely to be economic if either you or a commercial transformer winder does the job. It is a custom transformer as it is effectively a valve preamp + solid state power amp transformer built on one core. Easiest solution (and it might even fit in the box) would be to get two toroidal transformers - the first with heater and plate windings and the second with suitable power windings and then mount #1 on top of #2