peavey 5150 212 won't power on

[Funeral]

Hello all. My peavey 5150 combo amp has decided to not turn on. I went on vacation a week ago, came back and thought I was going to play some guitar. i plugged my amp in, and flipped the switch. Nothing. Checked the fuse on top, no response. I'm not an expert at electronics, so I have no idea. Some things to consider are the fact that the ground piece that plugs in is broken off. If I accidentally plugged it in backwards(if there is such a thing) would it ruin it? I may have, as I was doing it in the dark. Or maybe the power surged when I was on vacation. something of that nature. Also, I noticed the standby switch was in the on position when I went to turn the amp on. could turning off the power if the standby wasn't turned off first do damage? I really have no idea what to look at, but I'm pretty smart so I should be able to hopefully figure it out if you guys have any ideas of what the problem could potentially be. Thanks much in advance!

[Funeral]

Update...I left it in the on position for a while, and neither of the power lights are coming on, but both of the power tubes are lit up, one much brighter than the other, and the pre amp tube furthest to the power tubes is lit up, but the rest aren't working. I've read that there is more than one fuse in this thing, but I have no idea where to look for the others. Also, I've read almost all problems in fuses blowing comes from tubes being bad, so is that what I'm looking at? I'd truly appreciate the help, I only make 200 dollars a week and have many bills and things to pay, so I don't think I could afford to take it to get worked on.

[Enzo]

First of all, the voltages inside the amp can KILL YOU. If you go inside, always work with the amp unplugged, and I'd wait 15 minutes.

There are fuses inside, and it sounds like one or more may be blown.

[Jazz P Bass]

Peavey 5150

The ground pin on the power plug is there for safety.
Without it, you run the risk of being electrocuted if the chassis of the amp gets live voltage on it & you touch Earth Ground.
It being missing should have nothing to do with the amp turning on or not.
Be aware that you are running a risk.
Due to the fact that the amp is not functioning properly, your risk just increased.
That said, the polarity of the plug should have nothing to do with the power problem.
Turning the amp On with the standby On should not have made the amp fail.
Turning the amp Off with the standby On should have done no harm.
The other fuses are internal.
As to what is wrong, you are going to need a DVM to do some basic tests.

[Funeral]

I hate to sound like an idiot, and I have read about the voltages being able to kill you, so you should wait fifteen after unplugging it to work on it, but where are the other fuses that aren't the obvious one? I'm looking in the back where the tubes are located, and I don't see anything. Is there a compartment or something? should one of the power tubes be glowing more than other, or is that a sign that one of them is blown, and that's what is blowing the fuses that I can't seem to find?

[Enzo]

The secondary fuses are inside the chassis. The whole amp chassis has to come out of the cabinet to access them.

As to glowing, if you mean the little orange glowing heater in the center of each tube, some stick out the end a little farther than others and look brighter. That would be normal. However it is conceivable you have a tube with an internal short to the heater causing some such excess brightness.

[Funeral]

Okay, I've freed the chassis and have a view of the fuses. Stickers below the fuses say f2a, f8a, and f2a. I assume these are the type that I put in the corresponding positions? Should I just try replacing these and seeing what happens then? Nothing on the fuses looks particularly out of order or anything, but I don't know if you can tell when a fuse is blown.

[Jazz P Bass]

Fuses

F2a is a 2 amp fuse
F8a is an 8 amp fuse.
There are slow blow & fast acting fuses.
If there is a number stamped on the fuse, this will lead you to what type it is.
Slow blow usually have a "t" stamped on them.
It is imperative that you properly identify the fuses.
The wrong current rating or the wrong type is a recipe for disaster.
Do you have a voltage meter?
It really would help in diagnosing the problem.

[Funeral]

No, I do not have a voltage meter, it sounds useful and I'd like to get one, but I think it would probably be out of my price range at the moment. There's also a f1a fuse, but I imagine that's just a 1 amp fuse. I'll take a look and see if there's some kind of stamp on the fuses indicating whether it's slow burning or fast acting. If I can't find anything with that, maybe I can look up the schematics and find out from them or something? Would it be wise to put new fuses in and try it out to see what happens or what? If they blow immediately, is it likely that my tubes are the culprit? i guess this is where I'd need the voltage meter.

[Jazz P Bass]

Peavey 5150 fuses

Alright, I have a 5150 EVA on the bench.
Sheesh. I thought the Classic 30 was hard to work on. This thing is tough.
I may be wrong but it appears that the 6L6 board is riveted in!
Good luck working on that board.
Anyway, all the fuses in the 5150 are Fast Acting type.
The mains fuse, on the control panel, is 3 Amp.
The internal fuses, from back to front are:
F1- 2 Amp: B+ 480Vdc: Screen Vdc
F2- 8 Amp: Filament A Vac
F3- 1 Amp: +25Vdc - 47K to Filament A: Bias -50Vdc: Indicator lamps
F4- 1 Amp: -25Vdc
It appears that the indicator lamps are turned on by the screen voltage, by turning on Q13 through a voltage divider.

[Funeral]

Well, as an update, I went ahead and switched out both power tubes, and the phase inverter preamp tube. Then, I replaced three of the four internal fuses with the what I pulled out of there. I pulled two 1 amp 250v fuses, one 2 amp 250v, and there was an 8 amp ceramic one in there, but i couldn't find a replacement for it, so I left it in there. Powered it back on, it seems to work fine now. The fuses I bought didn't seem to be as specific as the ones that you have listed, but they do seem to be the same as the ones I pulled out. I don't know, I'm certainly not a fuse expert. I hope putting in standard radio shack type fuses doesn't do any damage or anything.

[Jazz P Bass]

Peavey power cord

And of coarse you bought a 3 prong replacement plug.
Right?

[Funeral]

No, I didn't. I'm not entirely sure where to buy those, and how to install one? It sounds as if there could be a large chance of failure in attempting that if I don't know what I'm doing. If it's easy though, I'd love to do it.