How do i repair a Marshall model 3210 100 Mofset amp that powers up but low or no sound at all

SOURCE: Hello, well i just bought

First make sure your guitar can't "hear" the amp as the sound can rattle the strings and have a form of feedback. Stand with your back toward the amp for example. If that doesn't help, take your guitar to the dealer and try it on another of the same type... see if it does the same. Also where you use it, make sure nothing is rattling in the area that can fool you as to how it sounds...

SOURCE: low volume on my marshall

I am very new here and don't know how to answer a question to a specific problem so I will write about the most common problems that I have had over the decades doing guitar amp repairs. If you find that your amp is extremely low in volume and then suddenly comes back to normal- check out the effects return [or power amp in] jack. Especially in Marshall amps-these corrode and your signal dies. If there is loud noise such as hissing and crackling with no guitar patch cord in the input jack- the input jack is likely at fault. They normally have switching contacts that ground part of the input circuit when the 1/4 inch male plug is disconnected. When this in is corroded or too weak to make normal contact, you can get these symptoms. If your amp is a solid state Marshall or Fender and there is a random buzzing sound with no guitar signal connected- hit the side of the amp and listen for the buzz to go away or become louder-if it does, this usually means that the connections are loose at the two large filter capacitors. In one or more Marshall amps, they use a filter circuit in the low voltage power supple for the preamp tubes. If you encounter a dead Marshall[the model escapes me now] remove the circuit board and resolder the four connections at the bottom of the bridge rectifier. If you have any other amplifier repair questions you can email me direct at [email protected].

SOURCE: Marshall 600 silver series bass amp head

Hi, what speaker do you have connected directly to the head? What output are you using to go to the PA?