Searched but did not find anything. Just bought a used Rumble 100 that has a buzz when the bass is close by. I know it is the amp as the previous owner told me about it also and the bass and cord are fine with my Rumble 150. I suspect a component has come loose or the internal foil RFI shielding has been compromised. Took out the four top screws but amp does not want to come out. Looking inside the slots the foil looks messed up and thought maybe the amp was jammed in. Before I hit it with a rubber mallet are there any other screws holding the amp in that I have not found yet? Also does it come out from the front or back? Thanks! Now fixed...see below.