How do I stop my MG100HDFX from picking up radio stations........I CANT PLAY LIKE THAT!!!!!

Output transistors, or output transformer.

If he KNEW it "just needed a fuse", why didn't he "just" replace it.
Could have sold it for a lot more if it worked,
The fuse is on the end of a circuit board right behind the power transformer, It should be a little glass fuse.

Yep! These poor quality jacks become "unriveted" and break in half. This is a fairly common occurence. Don't be afraid to unscrew stuff. USUALLY the corner protector screws are NOT necessary to take out. OFTEN the screws for the handle need to come out and any other screws from the top and the sides in the vicinity of the amp portion need to come out. Just keep track of where they go. The jack MAY be a part of the circuit board and you will need to get an exact replacement. NOTE: If it is mounted on the circuit board do NOT overtighten the panel nut as that can "de-rivet" the brand new jack !!! They are really poorly made...

the second jack is usually for a second cabinet.



http://www.marshallamps.com/downloads/files/MG100%20hbk%20Eng.pdf



here's a link to the manual. to be sure.

if it has effects on it, you may require two cabinets for the stereo effects. in the truest sense of stereo is what i mean.

Likely the filter capacitor(s) have failed OR the power amp has shorted driving DC with ripple into your speaker (very bad). Take it for repair before damage might be done.

This is either a shorted component in the power supply section or in the power amp electronics itself. Continuing to replace a fuse MAY damage additional components. Take unit in for servicing.

If the guitar can "hear" the sound, the strings can resonate from the sound and result in feedback. Running at maximum gain is asking for trouble. That causes distortion which drive the speaker as a square wave and worsens the problem. Also back off the treble as you can have supersonic feedback that you can't hear but will heat up your amp.
Test by allowing the feedback and then dampen the strings... if this stops the feedback you need to move the amp away from the guitar. Being a passive pickup makes NO DIFFERENCE about the problem.

The input jack is likely broken... a COMMON problem.

To avoid this in the future, loop your guitar cable through the handle so when cord is yanked it doesn't break the jack by yanking it sideways.

sounds like the effects module has stopped working . you could try re-working the joints around the i.cs on that board if you have a rework station. i have only managed to repair one baord this way suggest replacement is the best course of action. uk cost of panel approx £50.00 + fitting

First of all I would call the radio station and let the know that there over modulating just a bit.this has happened to me a few times even on my tel/phone. I use to get WOKO on my amp. You can try and move the amp to diffrent location , reverce the polarty switch on the back , not much more you can do. But watch out when you here music comming from you toster your in big trouble, just kidding. Good luck DFD