ANy competent amp tech can handle this repair.

Look inside your reverb pan.  The innards are suspended inside by four short springs.  It is free to bounce around.   Make sure it hasn't been bounced up and on top of the little posts.  Also check that one of the long springs has not broken.

If you have a stereo receiver, you could even run the preamp out of the amp to an AUX input on th receiver for a listen.

With NO footswitch, does the channel select switch work?   And does the reverb work?

What resistor that connects to the rest of the amp?  You mean R110?   Please use part numbers.  If R110, is there about 30vAC on one end?

Not sure why we would change a bunch of diodes.

Look at your schematic, at the footswitch circuit.  See all those test points with voltages for switching conditions?  How do your voltages compare?

Well it could be anything in the circuit.  The 10 year old thread is about an MA104, and you have a MA007.  Are they the same inside?  I don't know.  Can you post a schematic?

Saw a cheap camera advertised as having a "genuine non-achromatic lens".


And I bet the amp is also gluten free.

100% analog?  My how clever.   That simply means there is no digital in it.  Like no DSP or anything.    Imagine I market a TV set with "genuine full manual direct wired controls".  It just means it doesn't come with a remote, you have to walk to the set to change channels.

You have three LEDs - plus power indicator -  A, B, and P?  I'd wager channel A, channel B, and Peak.


I'd check the IC for function

I think the lesson there is don't just flip an amp on and crank a power chord without at least checking the amp.  AANy amp, ever.

I did, it grew.  I had options of huge or tiny.  I like a pdf so I can grab the part I want and make it the size I want.   I'm not complaining, I am just picky.

That^^^^

SOlid state amps do not need a load.  TUBE amps always do.

I can't read yours, but I have the G100-3, which looks the same other than power.

May I suggest, just unplug the speakers?  The schematic and parts layout shows the speakers plugging into the rear panel jack.

And electrolytics do dry out with age, but the little film and ceramic caps should last forever.   REALLY OLD caps like the wax covered ones in really old tube stuff will need to be changed as well.

And I agree, on these little practice amps, it really is unlikely you need to change out the caps at all.

And at the other end?

Feedback is one form of oscillation.  There are others.

The schematic does not show the PA jack tip connected to R1.   The tip is pin 2, which when plugged connects through auxiliary contacts 5 and 6 down to R99, which is the power amp input.   R1 does not connect to ground, it runs through the other auxiliary contacts and then back over to the input jacks.  It is part of the mute circuit.

Disagreements are not offenses  This is a forum, I stated my thoughts and not everyone agrees with me.  That is fine, and that is how we learn things.