Mesa 50 Caliber issues (need help)

[Tubesound]

Hey guys. I literally got for free a Mesa 50 caliber 1x12 combo with the 6L6 power tubes. Unbelievably from the trash!! yes the trash. It looked very clean outside and in. The tubes appear to be Mesa Tubes, with the Mesa MC90 cone. The cone is torn, so I am running the rig out at 8 OHMs to a seperate cab.

Heres the thing. I turn it on, warms up, I can play it for about 20 minutes, then sound seems to "cut out" . If I switch the standby switch off and on, it solves the problem for a few minutes. However after searching on here for answers in posts, I found a partial answer? Someone said run a 1/4" cable thru the in an outs of the FX loop. I did that, and now it only cut out once..

So what gives here? I never owned a tube amp and I cant believe my lucky stars that I found a somewhat working Mesa in the trash. Do you think this is a tube issue? or electronic issue? IS this worth fixing? Who would I send it to for repair? Im located an hour north of New York City if that helps.

Thanks gentlemen for your wisdom!

PS, I left the amp on, with bass plugged in, volume on 5. So after about an hour of sitting, the cabinet started getting a low sounding bzzzzz. I tried playing the bass, but no sound now. I flipped the standby switch and its back working again. hope this helps

 

[domct203]

Great find!

A few things to remember with tube amps.

Never operate one without a speaker hooked up or you will damage the amp if you do. Also, the amp will store up to 500 volts, even when unplugged, don't go aimlessly poking around in there.

99% of tube amp problems are usually tube related. If you are not blowing fuses, I would expect a faulty preamp tube.

I would pickup a couple of Mesa 12AX7's and replace one at a time until you find the bad one. Starting with V1, or the preamp tube closest to the input jack. Swap it for a new tube, and see if solves your issue. If not, put the original V1 tube back in, and move on to the next one. Repeat until you find the bad one.

IMHO, the best place to send the amp for repair is a Mesa Boogie certified repair station. There is a list of them on Mesa's website.

HTH,
Dom