#1
Normally I would just go and search for the problem.. but in this case my search has gotten me no where and this amp is pissing me off. Basically here's the deal. The tubes in the back have a slight orange glow when I power it on. Standby light doesn't come on. Changed the fuse in the back. Nothing happened. Tubes where replaced with new ones like 6 months ago. One day it was working great. Turned it off like normal. Came back about 4 hours later, went to turn it on, and nothing happened. I would rather see if I can fix it at home without having to pay a tech to do it for me.

Any suggestions?
#2
I don't want to sound like an a**hole but the better solution would be to take it to a tech, unless you're very savvy on electronics.
Even God has a Hell, his love for Humanity.
by Friedrich Nietzsche

Call me Edge
#3
That's what I was afraid of. I called a local tech but he's closed today. I took some electrical engineering classes in college but that was a few years ago and I wouldn't consider myself an expert. I was just trying to save a few bucks.
Last edited by NeverGonnaGetMe at Jan 30, 2012,
#4
Check the HT fuse on the board. All you're getting is heater current on the tubes, so you're losing the plate current somewhere. Hopefully it's that fuse and not the power transformer.

A blown power tube could be the cause, though not necessarily the entirety of the problem. Check the fuse first - if it's fine, you have bigger problems and it probably needs to go to a tech.

Be careful checking the HT fuse. The fuse itself isn't dangerous but the filter caps store quite enough charge to ruin your day (and pants) even when the amp is unplugged.
#6
Similar, yes. If you pull the circuit board out of the amp you'll see it right away. It's the only thing that looks like a fuse. I can't remember if there's more than one board fuse in the 5150, but if any are blown they'll point towards the issue.
#8
Take all the tubes and cables out, then unscrew all the chassis screws. The chassis is the metal thing sitting inside the head unit. When you pull the chassis out, the circuit board will be naked on the underside of the chassis. It's basically an upside down cake pan but instead of cake there's a circuit board. It's not too difficult, just don't leave it plugged in, don't touch anything that's not the chassis itself or the fuses, and don't drop it.
#12
please report back so we know you didn't kill yourself.


but Colin is right, as long as you don't touch anything but the fuse you'll be fine. best advice is to never put two hands in an amp chassis at the same time - put one hand in your pocket.