MG50CFX Repair

[JakeSteel117]

I have this old amp that a buddy of mine gave up on and I took it off his hands. The problem with it seems to be none of the effect knobs work, on any of the channels. Gain, bass, treble, none do anything. Reverb, chorus, flanger etc don't work either. Which means all the channels effectively sound the same, almost clean and bland. Except for the clean channel, which doesn't give any sound output at all.

If I turn these knobs while the amp is on, it makes an odd "static-y" sound as well. Also when I plug my grunge pedal into it I do get distortion.

Any ideas on the problem here?

 

[Roberto.]

I have the same problem with my Marshall Mg30cfx, but it doesnt work at all. I took it to a repair shop and they told me it was probably the fx/reverb board, and that they cant repair that, so I am also looking where to buy a replacement, or if anybody knows how to repair that, but thats maybe just my case.
I think you should probably first have a look inside and check if the cables are correctly place into the fx board and be shure the amp it is not connected to electricity.
I ended up buying a new dsl40cr. (You cant find these MG replacements in my country, you probably need to get it from another mg amp). The solder job is bad in the MG series, I broke the mp3 jack socket.

 

[ampmadscientist]

I have this old amp that a buddy of mine gave up on and I took it off his hands. The problem with it seems to be none of the effect knobs work, on any of the channels. Gain, bass, treble, none do anything. Reverb, chorus, flanger etc don't work either. Which means all the channels effectively sound the same, almost clean and bland. Except for the clean channel, which doesn't give any sound output at all.

If I turn these knobs while the amp is on, it makes an odd "static-y" sound as well. Also when I plug my grunge pedal into it I do get distortion.

Any ideas on the problem here?

This is the bottom of the Marshall amp line. The cheapest model.
It costs more to fix it, then the whole amp is worth.
People almost give these away when they DO work.

 

[JakeSteel117]

This is the bottom of the Marshall amp line. The cheapest model.
It costs more to fix it, then the whole amp is worth.
People almost give these away when they DO work.

Not really the point. I'm definitely not paying somebody to fix this for me. I've already taken it apart and looked it over myself. Just asking for some advice, if anybody had an idea of the problem with it is all. If I can fix it myself, that'd be great. I enjoy taking stuff apart and making repairs.

 

[darrenj7]

...this is how I fixed mine...