Blues Jr. Repair Question

[tomteriffic]

The teen-age son of a friend is a harp player and his rig consists of a Green Bullet and a Fender Blues Jr. He has run it pretty hard, anywhere from 1 to 5 gigs a week for about 2 1/2 years. It recently started fading and cutting in and out so Dad replaced the tubes. Now he gets no sound at all, other than a barely audible hum. And he says the tubes are running very, very hot. This happens with both the old and new tubes. He needs to get it fixed and quick and asked me where a tech might want to look first, just to save some time. I thought of a couple of possibilities but I'm way past my prime on this stuff, so I'm curious too.

Any suggestions?

[Thundernotes]

The teen-age son of a friend is a harp player and his rig consists of a Green Bullet and a Fender Blues Jr. He has run it pretty hard, anywhere from 1 to 5 gigs a week for about 2 1/2 years. It recently started fading and cutting in and out so Dad replaced the tubes. Now he gets no sound at all, other than a barely audible hum. And he says the tubes are running very, very hot. This happens with both the old and new tubes. He needs to get it fixed and quick and asked me where a tech might want to look first, just to save some time. I thought of a couple of possibilities but I'm way past my prime on this stuff, so I'm curious too.

Any suggestions?

If the tubes are really hot, he should check the bias voltage on the power tubes. But since he's getting no sound out of it, I suspect maybe a loose pin on one of the preamp tube sockets.

[Armitage]

I wonder if he unplugged the speaker while changing the tubes... assuming maybe the hum is just tranformer hum.

[Brewmaster]

I did the "BillM" mods on a bunch of these and can tell you that these things run really hot stock and the power tubes(EL-84's) are pushed to their limit and beyond. If he was in there messing around it is real easy to disconnect a clip coming from the OT. Like Thundernotes said it is also easy to disconnect a wire from one of the preamp tubes. Sounds like he missed reconnecting something. I think if he missed connecting the speaker the fuse would have blown.

[tomteriffic]

Thanks, guys, I'll pass the info on.