Sunn Model T blasphemously called a reissue even though it is just a beefed up Fender Evil Twin. Obviously it has nothing in common with the original Sunn Model T — it is just a modern 2-channel amp with a clean and a high gain channel.
Unfortunately if you actually have to replace anything you have to pull out at least a dozen push-on connectors coming from the power transformer and more. Very time consuming and still nearly impossible to get the board out. I dread the era when these amps start needing power supply recaps!
One huge single PCB is quite a hassle.
The volume would intermittently cut out. If you bang on the amp it would come back to full volume for a bit but definitely not reliable.
A power supply dropping resistor has burnt PCB underneath it.
Viewing the same area of the board as the previous picture but from the bottom side you can see the trace that connects to the power supply dropping resistor has broken off the PCB. Between the two traces you can see the charring of the board on the other side. The component must be hardwired because the PCB is damaged.
Sunn Model T preamp schematic
Sunn Model T power supply/output section schematic