Can you help me fix my amp?

[BuddytheReow]

I've got an old Marshall MG30 that I keep in my home office for noodling around. I had the power switch break off this afternoon (it's a simple rocker switch). How would I go about fixing it? I'm assuming I need to take the amp apart and see if there are other stray parts that broke off. I already tried shoving it back it but it doesn't work. Is this something a pedal builder can fix or is it better to take it to a local shop?

 

[Paradox916]

crack that sucker open and replace the switch, shouldn’t be terribly difficult. If you can build a pedal you can replace that switch.

 

[BuddytheReow]

Should I be worried about high voltages? Like I said I’ve never done amp work before

 

[Coda]

You would even need to solder. That plug probably has three push on wires…

 

[Harry Klippton]

Bust it open. There are usually screws on the top of the cabinet that hold the chassis in. Take those out, disconnect the speaker wire if it's easily disconnected. Slide the chassis out the back of the cabinet, and set it down on your bench. Get your meter out and hook it to the chassis, like in one of the holes where the mounting screws go. Check the filter caps for voltage (with one hand. That's why the ground lead is hooked to the chassis) then investigate the broken switch

 

[ICTRock]

https://www.tubesandmore.com/products/switch-marshall-style-rocker-power-mg-amps-black

there I fixed it for you

 

[owlexifry]

Should I be worried about high voltages? Like I said I’ve never done amp work before

nope. there are no dangerous voltages inside this amp (it's all ICs, no tubes)

(except for at the power switch & power transformer, but they won't be a risk while the amp is not plugged in)

just a good ol +15V/-15V supply.

https://elektrotanya.com/PREVIEWS/63463243/23432455/marshall/marshall_mg-30dfx_sch.pdf_1.png

^ looks like the switch you need to replace is just a SPST

 

[BuddytheReow]

Thanks, guys. First step will be to crack open the amp to see what im working with. Hopefully I’ll have time this weekend.

 

[Coda]

https://www.tubesandmore.com/products/switch-marshall-style-rocker-power-mg-amps-black

there I fixed it for you

You would even need to solder. That plug probably has three push on wires…

Goddamn it…

 

[BuddytheReow]

Took only a few minutes to take out the chassis and disconnect from the speaker. I took pictures to make sure I wire it back up properly. No soldering needed! (Actually, kind of a bummer). I will, however, since I need to buy a switch, I'll pick up another push button switch to solder in there. It's been giving me problems over the years and its only a few bucks.

It's kind of funny seeing common pedal components like a 4558.

 

[Harry Klippton]

You can use contact cleaner in the push button switch

 

[BuddytheReow]

Yea. I don't have any. I figure it's cheaper just to replace the switch.