Tourmaster combo -- troubleshoot help

[jfb23]

Owned Tourmaster combo 4212 for about 9 months.

With guitar plugged in, randomly makes a loud, thump-pop-crack noise.

Intermittent thump noises from the speakers with no guitar or anything plugged in.

If I gently tab the top of the cabinet,crackling noise occurs.

I recently had warranty work done on it, two months ago, where Egnater replaced
a burnt power rectifier in the amp.

Any ideas of what could be causing this new problem.

Thanks.

 

[Len Rabinowitz]

That is almost certainly a bad tube or tubes and is no big problem. Were it me I would just get a whole new set. I would then test the old ones, through out the bad one or ones, and have a few spares. Or, you could buy one or two power tubes and one or two pre amp tubes and just keep swapping them out until you find the one or ones that are bad.

You might also just make sure the tubes are well seated in their sockets. They can come loose sometimes.

 

[jfb23]

Thanks Len.