second series punch75 (pre-HD) trim pots

[Clipped]

what in the world are those trim pots for inside the amp and how are you suposed to adjust them?

i got itchy and turned one to see what would happen , the next thing i saw was magic smoke

 

[Perry Babin]

If they're like the ones in the attached image, they are the bias pots. They set the idle current for the amplifier.

 

[rustyjeeps]

It's the smoke screw.