#1
Hi!

I bought my marshall jcm 800 about 6 months ago, and it worked fine for about 3 months, and now i feel like i really need to do something about it.

The problem is that when i play to loud, or "trebely" enough, is just dies. At least i think that's the cause. I have to push the "Reset" switch on the back to get it working again.

I play it like this (When gain channel is turned on):
Master volume: 3-4
Volume: 9
Gain: 9
Persence: 6
and the other knobs are at 12 o'clock.

Sometimes the shutdown occurs when my boost pedal is on, it's in the fxloop and makes is sound more and adds some gain, that's why i think it's volume/treble related.

I opened up the back and took a look at the tubes and they all light up and seem to be fine when i turn the amp on

The amp always stays "medium" warm when i play, and by that i mean that i dont get burned when i hold my hand on it but i can still feel that is warm while turned on.

Iv'e tracked the serial number and its a 1987 model, if that helps.


I have some upcoming gigs and really need to fix this fast, wouldn't wanna buy a new amp for 4 gigs and then get back to solving this problem

Thanks /John
Last edited by Dormpatrol at Mar 15, 2011,
#2
Oh man, you got one of those import model 2210's don't you? No fuses.

I'm thinking you have power valves that are failing. I would replace them.
Tastes like chicken, if chicken was a candy.
#4
Quote by ConfederateAxe
Oh man, you got one of those import model 2210's don't you? No fuses.

I'm thinking you have power valves that are failing. I would replace them.


Hmm, yes i read something about it last night on a website.
There is said that if the sound has started to get less "punchy" and losses it attack, and just gets overall a bit messy, starts to hum at a low frequence and then shuts off it would be the power valves. And that's kinda much exactly what happens.

Quote by AcousticMirror
reset switch...is that a circuit breaker?



See that little red buttom there?
http://farm3.static.flickr.com/2701/4335761025_29342f4de3.jpg
Thats how it looks. Thoug that's not my amp nor my amp model.[/
Last edited by Dormpatrol at Mar 16, 2011,