5150 - No Sound. HELP!!!

[Jtwusmc]

Last night I purchased a Peavey 5150 block letter Amp (the first model 5150 I). When I got it home, it sounded like complete crap. The volume was very loud even with the dial just above 0. It had a lot feedback and was all tone with very little bottom end. This was the most evident in the lead (high gain) chanel, however they all sounded scratchy and piercing. Peavey 5150 Amp

After about 10 minutes, the amp stopped making sound all together. Everything powers up and all the tubes still glow (orange). All the chanel lights still work and go off an on, but there is no way at all to get any sound out of this amp now. NONE, not even a hiss. The cab is like it's off...

I know a new set of tubes is going to greatly help out many of these issues, but my question is, would the tubes also be what is impacting the master volume being too loud or would that more likely be a bad pot? Also, is it likely that a bad tube(s) is the cause of all sound disappearing?

Thanks!

[Enzo]

I'd first look to the high voltage being gone - a blown fuse - and that likely from a failing power tube.

[damus]

Hope it's not too necro. My random thought's from reading this was that 5150's are ridiculously loud just past 0, even taking out a pair of power tubes and halving the impedance doesn't reduce the volume by a noticeable amount. I've found that worn out tubes lose treble in my 5150 not bass. I know this will sound stupid but my first guess would be the speaker cable or the connections on the back based on the description, second thing I would do is pull it appart and look for possible mods done to the amp. I havent had a fuse blow in a 5150 and found them quite reliable in that aspect, what are the tubes that are currently in it?
(I'm no expert though, just trying to help)

[Enzo]

Fuses on them don't usually blow out of the blue, it is almost always because a power tube failed. It is easy to tell from the outside come to think of it. The power light comes on with the power switch. The status light - some call it the standby light - only comes on when high voltage is present. Blown high voltage fuse and no green status light.