#1
My Classic 30 has gone kaput - not the first time it's done it. I'm not exactly sure what's wrong with it this time, I've looked at the guts and I'm still confused.

Little background info: the first time it died, I ended up taking it to an amp tech and he ended up replacing the stock power transformer and it put the amp back on its feet. As I understand it, the stock power transformers in the Classic 30s are quite piddly and not really up to the task. Since it's been replaced with a beefier one this leads me to believe the transformer's not the problem, but I could be wrong. The symptoms for that problem were that the tubes were off but the pilot light was on.

A few months back I switched on the amp and left to let it warm up. When I returned 10 minutes later the pilot light was off, nor were the tubes lit. So, I opened up the guts and the only thing awry was that the fuse between the power cable and power transformer had blown. I went to Radio Shack and bought a couple more fuses (rated exactly the same) - didn't bother putting one in because I know that fuses usually don't blow on a whim.

Today I looked at the set of tubes I was previously using. One of the power tubes was definitely bad because the shiny surface on the wick side was gone and the shiny on another power tube's wick side was about half gone. I replaced the power tubes and put in the same set of preamp tubes (which look fine), put in a new fuse, and fired it up. The pilot light lit up and then died after about a second, obviously the fuse blew again (the pilot light is wired directly after the fuse). This leads me to believe that the problem doesn't lie with the tubes, although the bad tubes I replaced definitely may have contributed.

I've got a couple ideas for why it's not working.

The first is that the power cable died, I've never heard of it happening but I guess it's not entirely possible. I don't go out of my way to take care of it but I don't think I beat it up either. I do loosely fold it up (not in a tight knot or anything) and tuck it inside the amp cavity when I go to band practice several times a month, so that might be the problem.

The second is that some of soldering holding the wiring together just before the power transformer is failing. I checked it and it looks ok but looks can be deceiving. Haven't tested it with a voltmeter yet, but I sorta doubt the efficacy of that seeing as the amp itself gets no juice.

Also, I'm wondering if the problem couldn't be with the preamp tubes. I have two sets of power tubes and preamp tubes that I bought from eurotubes. One of them is the standard retube for the C30 and the other is the blues option for the C30. Since power tube set #1 failed, I mixed power tube set #2 with preamp tube set #1 (I can't remember if I had the blues tubes or the standard retube when the amp failed, so I'm not sure which set has the bad tubes). Is this okay to do?

Any thoughts? I'm not really at my wit's end but I have no backup amplifier for band practice, and after several months I really want to play my electric geetars again. Thanks in advance!
Last edited by AK501 at Jun 16, 2011,