Can a novice repair a solid state amp?

[spiral]

I think i found the problem yesterday. The reason the knob sticks out is because the pot that is on the reverb is THE WRONG POT. it's simply the wrong one. Maybe the original pot was broken before and someone tried to fix it and bought the wrong one, put it on without realizing it was wrong, then sold it. Anyways I ordered the right one, along with soldering gear, and i'll try to fix it when everything comes in.

Why do you say it's the wrong one? In your photo it's a B10k pot, same as VR7 (variable resistor, linear taper 10k) in the schematic.

[prsguitar]

I don't know the names of the parts of a pot, but the metal shaft that sticks out that allows you to stick the knob on is just different. It's much longer than the rest of the pots. I don't know if that has anything to do with the functioning of the pot, but it is definitely different.


B10K or 10K Potentiometer

the broken reverb pot is the ".531 watt", the rest on the amp are the ".335 watt" styled pots.

[ColMc]

Mate, I wouldn't be too worried about the knob sitting a bit proud.
They're made in different physical sizes including the length of the shaft.
As long as the value in Ohms and the audio taper is the same as in the schematic it will be fine.
You can test the pot with a DVM.
Have you checked the solder joints on the board?
Cold solder joints have a distinctive look about them.
Sort of a matte colour and wrinkled or cracked.
Cold solder joints can occur wherever there is high current flow.
So look in the area where the leads from the power transformer plug into the board.
A magnifying glass is a big help, start near the plug and fan out over the entire board.
Good luck.

[spiral]

I don't know the names of the parts of a pot, but the metal shaft that sticks out that allows you to stick the knob on is just different. It's much longer than the rest of the pots. I don't know if that has anything to do with the functioning of the pot, but it is definitely different.


B10K or 10K Potentiometer

the broken reverb pot is the ".531 watt", the rest on the amp are the ".335 watt" styled pots.

You need to know the names of the parts of a pot to order the right thing. Every part listed on the page you linked won't work. You need:

• B10k (B=Liner; 10k=the resistance value.) very important. If you get the wrong value it won't work or will work incorrectly. The rest of the things below are just for fit, but this one isn't negotiable.
• split shaft
• PC mount (the legs are straight and board-mounted like this)
• Measure the shaft of the pot with calipers, both length and width so it will fit both through the panel but also on the board