I own a Marshall MG30DFX. I have owned it for nearly 2 years and the warrenty has run out. The Amp has been fine untill this year...

Problem: The amps volume doesnt work properly and when I turn the volume up it doesnt get louder, all of a sudden the amps volume might randomly come up, but seconds later goes back down. I have tried replacing the volume pots but it made no difference. Its not my guitar or lead because they work fine on other amps. Even when the amp is nearly full volume the sound is quiet when it should be blasting my ears off!

Please help!

Jon Wilson, September 2008

Reviving an old post, yes, but it needed to be done. The MG series are SOLID-STATE amps... IE - there are no pre-amp valves, tubes, chokes (all mean the same thing). And yes, I am aware that the VALVEstate series uses valves in a hybrid setup: essentially half-tube, half-transistor. MG series does NOT.

To OP, it could be an number of things: if you are not confident diagnosing it, bring it to a tech. Solid-state amps are not as cut and dry as tube amps. You might want to check for obvious bad solder joints, but be careful when opening the chassis.

Mickey, May 2011

Sounds like the preamp valve may have died. Happened to me on a Valvestate 100 years ago. Best thing is to go see Marshall... they'll check the rest of it out and it will be like new!

Highwire, December 2009

I'm in the middle of the same problem on my MG250DFX. my issue is the connection between the 1/4'' input jack and the circuit board in the amp. not too hard to fix if you're handy with a soldering iron.

it's gonna be my saturday afternoon project. :-)

roytherocker, February 2009

I am having the same problem with my Marshall Mg250dfx model! quiet loud the quiet again a real pain! Have you managed to get yours fixed? I found that if i plug my Line 6 pod into the fx return on the rear of the amp thats its fine, try that if you have no sucess.

Nathaniel Watson, February 2009

most likley a soldered joint where the volume/gain pot meets the pcb,inspect the pcb for poor or broken joints

me, November 2008

Go and see a specialist

Professional Music Technology shops are very good at amp/guitar services, i'd see them.

Longy, September 2008