#1
Ok so my marshall MG30CFX has two overdrive's OD-1(light is green) and OD-2 (light is red) when I have OD-1 on the overdrive is fine but when I stick it on OD-2 it just makes a high pitched squeal, so if anyone knows the problem can they identify it and tell me how to fix it (and hopefully I won't have to open it up since I only got it late december last year)

Also I am using the TG-M amp settings for metallica's enter sandman which is
GAIN-9
BASS-10
MIDDLE-2
TREBLE-8
REVERBARATION-2
And no amp FX or any pedals used
Last edited by cha33 armstrong at Mar 3, 2012,
#2
I have no idea, some solid state component probably burned out. Chances are you won't be able to just fix it, as the PCB in those amps isn't really suited to finding and replacing single components.

You should still have a warranty, though, if you just got it last December. Take it back and get it replaced.
Gear
Highway One Tele (w/Custom Shop 51 Nocaster pickups)
Standard Tele (modded to Nashville specs)
Reverend Roundhouse

Orange Rockerverb 50 MKI
Vox AC4c1
Jet City JCA20H

And pedals!



"Shiva opens her arms now..
...to make sure I don't get too far"
#3
Diagnosing a SS amp in a forum is next to impossible.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#4
I am willing to bet it's the user. Turn down the gain to just enough to get the crunch you want, and don't be right by the amp. Is it loud?

It's not meant to be loud.
"If you're looking for me,
you better check under the sea,
because that's where you'll find me..."
#5
I think I know the problem: you have a mg30cfx.
Squealing happens if there's too much distortion. Especially with lower-end amps. Turn the gain down a little.
#7
Does no guitar sound come through, just the squeal?
Telecasters-->Dunlop Volume Pedal-T1M Pearl-AMT Japanese Girl Wah-Line 6 M9-Ibanez DE7-EHX Cathedral-->Mesa Boogie Nomad 4x10 combo
#9
It's busted, buy a better amp.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#11
You said it passes no signal and just sits there oscillating and you think that isn't busted? I don't know how to respond to that.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#12
Quote by Cathbard
You said it passes no signal and just sits there oscillating and you think that isn't busted? I don't know how to respond to that.


What so channel 1n2 work fine and so does OD-1 yet OD-2 is f**ked and there is no possible way to fix that???
#13
Maybe if I had it sitting opened up in front of me but as I said earlier, diagnosing a fault in a SS amp over a forum is practically impossible. It's a cheap shitty amp. To pay a tech to diagnose and fix the fault will probably cost more than the amp costs and certainly far more than it's worth.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#14
Wait shitty little amp, look I know it aint a 100watt or something of massive power but marshall is the biggest amp brand in the world and my first ever one is shit :'(
#15
It's not a Marshall, it's a crappy little SS amp with a Marshall logo stamped on the front.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#16
Quote by Cathbard
It's not a Marshall, it's a crappy little SS amp with a Marshall logo stamped on the front.


I guess until I get a decent amp with more watt I can live without OD-2
#17
You'd certainly be better off putting the money you'd have to pay to get it fixed into a savings account towards getting a better amp.
With Marshalls unless you see big glowing bottles in the back it's crap.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#20
I just picked up this amp a few days ago at a pawn shop. I tried out the clean, crunch, OD1 and OD2 channels at the store. They all sounded fine - no feedback problems. But like the original post, now it seems the OD2 channel ONLY has annoying squealing feedback. Again - this was not a problem in the store. Any advice?
#22
Stop using it.
Gear:

Gibson 2005 Les Paul Standard
Fender Road Worn Strat w/ Noiseless pickups
Marshall JCM 2000 401C
Marshall Vintage Modern 2266
Marshall 1960A cab (Dave Hill from Slade's old cab)
Ibanez TS9DX
EHX Little Big Muff
Freshman Acoustic
#23
Quote by eadavis80
I just picked up this amp a few days ago at a pawn shop. I tried out the clean, crunch, OD1 and OD2 channels at the store. They all sounded fine - no feedback problems. But like the original post, now it seems the OD2 channel ONLY has annoying squealing feedback. Again - this was not a problem in the store. Any advice?

Return it, ask your money back and buy a better amp.
Quote by AlanHB
Just remember that there are no boring scales, just boring players.

Gear

Bach Stradivarius 37G
Charvel So Cal
Fender Dimension Bass
Hartke HyDrive 210c
Ibanez BL70
Laney VC30
Tokai TB48
Yamaha FG720S-12
Yamaha P115
#24
Soz guys forgot about this thread turns out the problem is dust gets in the button so every so often I have to blow into it but the amp hardly gets used now I have a tube amp
You hit 'em and they get back up
I hit 'em and they stay down
- Frank Castle
#25
My Marshall mg30cfx has this static problem when I turn up the volume about a quarter of the way I get a lot of static out of all the setting (clear, crunch, od, od2) it never made any static when I got it and I've only had it for about 2 months now. If this is a problem worth sending in, would I be able to get my money back or would they just replace it?
#26
Quote by eadavis80
I just picked up this amp a few days ago at a pawn shop. I tried out the clean, crunch, OD1 and OD2 channels at the store. They all sounded fine - no feedback problems. But like the original post, now it seems the OD2 channel ONLY has annoying squealing feedback. Again - this was not a problem in the store. Any advice?


Yeah, read the thread. It's not worth paying someone to fix it. Either live with it or try to take it back and get a different amp or your money back.

It might be a sore point on the amps but no one has posted with a fix and it would be nearly impossible to attempt to lead to a proper diagnosis over a forum.
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
Last edited by R45VT at Mar 8, 2014,
#27
Quote by oreo1001
My Marshall mg30cfx has this static problem when I turn up the volume about a quarter of the way I get a lot of static out of all the setting (clear, crunch, od, od2) it never made any static when I got it and I've only had it for about 2 months now. If this is a problem worth sending in, would I be able to get my money back or would they just replace it?




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