Matchless Hotbox troubleshooting

[williammorgan1971]

Hello,

I was wondering if someone could help me narrow down what could be wrong with my Matchless Hotbox. I know this is a hard question to answer but I'm just trying to get a basic idea.

The symptoms:

The back lights up
no sound passes through
there used to be a crackle before the sound stopped completely

I've tried changing tubes but nothing changed.

This model has a history of transformer problems. If mine has the same problem would it still light up? Could a Cap. be the issue?

I'd take it to a shop but I'm broke.

Any help would be appreciated.

[52 Bill]

This model has a history of transformer problems. If mine has the same problem would it still light up?

There are two separate secondary windings on the transformer. One is for the filaments and the lights, the second is for the high voltage section. It could be that the filament winding is ok, but the high voltage winding has opened up.

In order to troubleshoot this you will need a voltmeter to check the voltages inside the pedal. If you have a meter, start by checking the high voltage power supply, to see if it's working.

Of course, this will require you to have the power on while checking things. If you don't feel qualified, take it in to a shop, or to someone else who is qualified to work on a live circuit.

[williammorgan1971]

Of course, this will require you to have the power on while checking things. If you don't feel qualified, take it in to a shop, or to someone else who is qualified to work on a live circuit.[/QUOTE]

Point well taken Bill. I can't say I feel qualified to check this thing with the power on. There's enough voltage to kill you(even unplugged). Your information about the power supply does lead me to believe that I have the problematic transformer problem. I could be wrong and it is just some other problem but it's not worth taking the chance on my life. This unit is flooded with 600volt rated caps. The schematics online don't even align to the current configuration.

I'm not going to say front face and bold that the transformer is to blame but I realize the circuitry is far more deadly than complex that baby steps are advised for those who do not understand the circuitry.

thanks.