Marshall MG100HDFX Volume Drop

[sixstringslinger21]

My MG100HDFX will randomly drop the volume to approx 50% of what I was originally playing on either channel. After turning the amp off and reseting it after 10 seconds, the problem usually goes away. Isolated it to the amp, no issues with wires or pedal I'm using. The problem sometimes returns, sometimes not. Very sporadic, very annoying. Any ideas? I gig quite often, so I can't afford to send it into the shop. Limited electrician knowledge, so please don't go overboard with schematics and such Thanks!

[Enzo]

OK. I will type s-l-o-w-l-y then.

Next time it does this, plug a spare cord from FX send to FX return. If this external bypass wiring restores the sound, then one of the jacks is bad.

[sixstringslinger21]

Haha I know this a late response...sorry. The amp was still under warranty and had it serviced, problem went away for a while but has returned (surprise surprise)... I put a patch cord from the fx send to the fx return, but the volume still remains extremely low. I did turn the FX loop mix signal level from "effect" to "dry" which seemed to correct the problem, but then again I have no idea if it was me turning the knob that fixed it, since the problem sometimes corrects itself at random without me touching a thing. The weird thing is I could still press the FX stomp switch and get a full FX sound from the amp... Think it's still a bad jack?