It won't power up when switched on; no signs of life at all. It worked fine at a gig and then when I got it home, it wouldn't switch on.I s there a fuse inside the cabinet? I've replaced the fuse in the plug, but that hasn't helped. 

Hey Mates,

Having issues with a clients amp, seems that after a retube that i did, he was playing and after about 30 min, it gradually started losing sound and then cut sound completely.  I did the re-tube myself, and biased it properly and i was able to play it for about 40 min with absolutely no issues.  List of troubleshooting steps i have done:

tried a different speaker cable

tried a different guitar cabinet

tried a different guitar and guitar cable

tried the old tubes, additionally bought a 12ax7 and tested each pre-amp tube

tried a different power source

Have tried different power tubes

have checked and replaced the fuses

Now this is what i am THINKING is the problem, I think it might be something with either the heater curcuit fuse, or i think it's called a BRT1 Rectifier?  I did alot of research and it seems that the people having MY issue, explain the same symptoms of what i am having.

Now i have to make this clear, I AM NOT A PROFESSIONAL TECH, just a guy helping bands out with tech stuff that they don't know how to do.  So any help is appreciated.

Thanks!