Question about Marshall Mg100dfx 100-Watt Combo Guitar Amplifier

2 Answers

Marshall amp goes quiet

My amp is about 4-5 years old and one day it decided to be really quiet and when i turn it all the way up it hardly puts out a sound. What could this be?

Posted by on


2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Marshall Master
  • 5,603 Answers

Often this is a broken input connector or an electronic failure such as a tube or semiconductor device.

On some units a failed switch on a jack for direct input to the power amp can cause this. Oxidation at the contacts causes this problem.

Posted on Apr 27, 2010

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert whose answer got voted for 20 times.


    An expert who has written 20 answers of more than 400 characters.

  • Expert
  • 73 Answers

Yeah i would consider replacing your eh preamps with some jj ecc83s pramps (its a 12ax7). also, volume loss is usually something shorting to ground, i would assume a smaller electrolytic cap in the preamp somewhere. look for bad solder joints and overheated areas on the circuit board, indicating a potential cold solder joint/ a cracked weld and resolder the part at the least. the parts that get the heavy use are the input jacks volume pots, etc. look there also for bad solder joints.

Posted on May 07, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

What would cause my Marshall Mode 4 amp to not change channels?

That can be caused by a faulty switch contact. I presume channels can be selected manually.

Aug 05, 2014 | Marshall Amplification Marshall AR-AM4,...

1 Answer

My Marshall 4502E Amp switches on fine. However when you flick the STANDBY switch on it blows the 1.3A Fuse every time. Any solutions, baring in mind I have checked all the diodes, resisitors, rectifiers...

I would first check the filter electrolytic caps for shorts...

This is the WAY you work on this problem. Replace the fuse and put a 60 or 100 Watt incandescent lamp in series with the HOT power wire. This acts as a current limiter/automatic resetting fuse and you can search out where the current is going. Old trick we have used for more than 50 years. Also using a Variac to control the voltage can be useful, but the lamp should get you through the problem...

Feb 10, 2011 | Marshall Amplification Marshall MG250DFX...

1 Answer

I've had (i don't know the model) a marshall 4 way foot controller (1.Clean/crunch, 2. Overdrive/clean overdrive, 3.Tempo, 4. tuner) for about 2 years now. Its been working fine untill i tried to plug it...

Make sure the pedal and the amp ae compatible. MANY pedals can only be used with one type and model amp. If this was used with a different model amp originally, it is probably incompatible with the ine you are trying to use it with now.

Jan 22, 2011 | Marshall Amplification Marshall PEDL90008...

1 Answer

Greetings. My MG 250 DFX Marshall 100W amp behaves strangely... I had some problems with it lately. I've been using it for a few years in my flat, so it has not been used extensively in terms of power...

I believe the design of this results in what you are seeing... Check each speaker INDIVIDUALLY plugged into the MAIN output as plugging into the second jack shifts the tap of the output transformer to the 4 ohm tap which results in a 6 Db drop but now you have two speakers... the apparent level change will be almost unnoticeable.. Do comparision of the speakers individually using the MAIN jack. This is just the characteristics of the beast...

Jan 11, 2011 | Marshall Amplification Marshall MG250DFX...

2 Answers

Wiring diagram pignose 7-100 guitar amp which wire goes where?

There are a couple thumbnail sketches of the diagram at:

They are down about 3 an 6 of the blogs.

Nov 29, 2010 | Marshall Amplification Marshall Mini Stack...

1 Answer

My Marshall mg100hdfx is a little over 2 years old and i never used it that much. I turned it on, made a popping noise and shut down. No smoke but i could smell a slight electrical burn smell. I never...

DO NOT try to use it until it is repaired or you may do further damage. Probably a capacitor shorted or a diode in the power supply. This is NOT DIY unless you are competent at electronic repair. When it is appeared to be restored, put a 150 watt lamp in series with the power cord to limit current till you know it is repaired... saves fuses and destroying further components if there are other parts that are bad.

Nov 03, 2010 | Marshall MG100HDFX 100-Watt Amplifier Head

1 Answer

No output from my Marshall MG15DFX

could be effects module or sound output i.c. also check send and return jacks

Feb 04, 2010 | Marshall Mg15dfx 15-Watt Combo Guitar...

1 Answer

I have a marshall avt 100 which was working fine until i plugged new guitar in strummed one chord and the speaker went **** up, so i plugged into another cab and played a while then a week later plugged in...

This is a problem I would recommend for a qualified Marshall amp service person to look at. Worst case scenario is that somehow the speaker out put transformer or the power transformer burned out. They aside from output tubes are the most expensive parts to replace. Add shop labor on top. Ask for an estimate first. Consider how much a new amp will cost and then decide. I would personally go for the repair myself.

Nov 27, 2009 | Marshall Mg100dfx 100-Watt Combo Guitar...

4 Answers

Marshall valvestate 8080 1. when i turn the buttons they make a cracking sound 2.when i play on it the sound becomes very quiet

When turning the knobs you might get a crackling noise if the amp is old, The knobs get worn. Either you can replace them or repair them with a tiny squirt of WD40. Check youtube videos for help.

As for the fading sound, That would be your valves ... They need to be replaced ... I suggest taking it to a repair dhop for that because they need to be matched.

May 22, 2009 | Marshall Music

Not finding what you are looking for?
Marshall Mg100dfx 100-Watt Combo Guitar Amplifier Logo

827 people viewed this question

Ask a Question

Usually answered in minutes!

Top Marshall Music Experts

Michial Gueffroy

Level 3 Expert

1138 Answers

matt martin
matt martin

Level 3 Expert

1212 Answers

Leonard Jeffrey

Level 1 Expert

6 Answers

Are you a Marshall Music Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides