No sound from speakers in my JCM 600!!!

[Matt123]

I am playing in a musical this christmas, and so have spent all day in rehearsals. However, about half way through my amp (a Marshall JCM 600 tube amp) stopped working. There is no sound at all, not even any buzz or hum.
I turned it off for 30 mins or so, then tried again - still no luck. I then tried connecting the effects send to another amp - and it played perfectly! Therefore, the amp itself works fine.
Any suggestions why it could have cut out, and what can be done to fix this?
Thanks, Matt.

[marvar]

Re: No sound from speakers in my JCM 600!!!

the first place to look is inside your amp- I have one of these
there are several internal fuses, one is on the power amp pc board-
just behind the capacitors- mine recently did the same thing- I just replaced the fuse with another 6.5 amp fuse and all is well- do you use a small fan in the back of it- maybe you should.

[Matt123]

Re: No sound from speakers in my JCM 600!!!

Oh wow, thanks for the speedy response! I'm not usng a fan n there at the moment, but thats defntly somethng to consider.
Will get a new fuse in there and see how it goes. Is the board easy to get out and work on?

[marvar]

Re: No sound from speakers in my JCM 600!!!

you don't have to take the board out- but it is a little tricky to get to the fuse- but it can be done- the board itself is mounted laterally it's the one in the middle, with all the tubes on it. it would be a real chore to get it out- but with a little patience you should be able to get to the fuse- you need to test it after you get it out- the fuse may be good, and it could be some other part that has gone bad.