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Switched my Marshall JCM2000 on today and no sound. The face LEDs light up but no sign of life in the valves..

Could it simply be HT fuse or is it fried?

OK, simple things to check...

1. Pull the chassis and check the fuses
2. When the chassis is out connect the speaker, pull each preamp tube and blow into the socket, plug in and out the tube a few times, try this with each tube switching on and chekcing for sound each time.
3. get another preamp tube and try it in each place.


How old is it?

About 4 - 5 years old, its that DSL 401.
Dont i need to let all the charge drain before i start messing with stuff?

Fran wrote:Switched my Marshall JCM2000 on today and no sound. The face LEDs light up but no sign of life in the valves..

Could it simply be HT fuse or is it fried?

Wot no glow? = no heater supply? = blown heater supply fuse?

NickS wrote:

Fran wrote:Switched my Marshall JCM2000 on today and no sound. The face LEDs light up but no sign of life in the valves..

Could it simply be HT fuse or is it fried?

Wot no glow? = no heater supply? = blown heater supply fuse?

Any of the preamp tubes not being seated correctly can cause there to be no glow also.

So you're out of warranty Fran? I would do all I've said and I'm sure you;ll find the problem. No need to drain the caps and you won't be prodding stuff too much, just be careful and have one hand in your kecks at all times.

Both fuses look okay. When i switch it on i get the 'hum' but no sign of life in the valves and no sound.
Which are the preamps, the three small valves towards the front panel?

Yup. Small ones are the preamp valves. Some of them will be covered by metal cans. Push down and turn the can to release.

Check all these. Unplug, blow, clean pins, replug - turn on amp, etc etc.

Mike wrote:Any of the preamp tubes not being seated correctly can cause there to be no glow also.

Series heaters? PITA.

I'm hoping it's just an unseated tube.

Nah, still nothing. Man them tubes are bitches to get back in.
Thanks for your help mike, but it looks like teh Carlsbro head & cab is gonna get more use untill i get this into the shop.

Buggeration. It might be worth buying a single preamp tube to switch into each place in turn and a spare set of power amp tubes to try first, could save you some money if it's just the tubes.

I feared the worst instantly. I had a lot of trouble with it the first year, the input jack, transformer and a few tubes went.
I'll see what the shop have to say on it. If its gonna cost me over a hundred quid it can sit for a while.
Once again, thanks mike.

no worries, I hope it's just tubes.