I "inherited" a Sansui 9090DB from a friend a few weeks ago, unit was/is pretty dirty, was in a garage environment most of it's life. Brought it home, plugged it in connected it to a cheap pair of speakers, and it had all kinds of static, drop-out in sound, etc. etc. Took it apart, cleaned all the switches, buttons, etc. Worked all the switches, buttons and applied some Faderlube. Put it back together enough to plug it in and fire it up. First, I checked the DC Offset for both channels per Echowars tutorial. Right was at 7-8 mV and Left was 3-5 mV. Both bounced around a little, even after 10 minutes or so. That looks pretty good. Plugged in some speakers, connected a CD player, and fired it up. Actually it sounded pretty good, some static still in the controls, but gently worked them out. Played it out for around 30-40 minutes, then noticed a drop in volume in the right channel. Went through and worked the controls a bit more, and noticed when I took the unit out of stereo mode into mono mode, the volume increased in the right channel up to the left channel level. Played around with this for another 30 minutes or so, no change. Swapped the speakers to make sure it was not a speaker issue, same results, right channel noticeably quieter. Before I take the unit apart and go through another cleaning cycle, I thought I may ask some more knowledgeable folks if I should be looking for another cause. Any clues or theories would be appreciated. As an aside, my goal when I took this receiver was to return the unit to my friend in a better working and "cleaner" condition, even though he thinks I'm keeping it.