lost sound in right tube mono

Bad Bias pot maybe????

check the fuse?

After I stopped whining and stomping my feet I did locate another fuse that lloks to be wired into one of the transformers (B+ rail?)
About a week ago I had a tube loose its bias,thats a sight to see,the whole plate structure glowing red.It ended up blowing the main power supply fuse,but I never bothered to check the other one(didnt know there was one til now)
I wonder if the fuse was damaged and not completly blown and just decided to let go now.
I will post after I power it up

Don't lunch too many tubes trying to diagnose it. Sounds like a bias supply problem.