Just picked up a 2105 amplifier with wood case in decent shape. Only problem it was known to have was the cracked glass front which I planned on fixing at a later date. Using a Marantz 2270 as a pre. Hooked everything up and get very faint sound out of the left channel. Swapped the cables at the pre-out on the Marantz and still have the same problem which narrows it down to the amplifier. Tried different speakers and speaker cable and still very weak left channel. Have some static when I turn the Left Gain all the way up and jiggle it. Proceeded to take the bottom off the amplifier and really deoxit the Right and Left Gains. Worked them each a good 100-150 times each until they were really smooth. Let everything dry and then hooked back up with the same problem. I'm thinking my next step is to take this somewhere to be serviced. Would have liked to have sampled it a little before the service call but thinking that I may not get that lucky. Just wanted to see if there is anything simple I could look for. I got the unit for a great deal so not worried about a service/restoration bill if it comes to that sooner than later.