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.
We would recommend that you have the amplifier looked at by a qualified engineer.