I picked up a SA 7500 MkII at an estate sale last week, and I ran into some problems which, after I did some researching on here, appeared to be very typical with this unit. After thorough Deoxiting, I continued to have a scratchy volume control with one channel that repeatedly went out. But if I turned up the volume loud, the channel would "push through" and come back. Following the information in this thread, http://audiokarma.org/forums/index....-7500-ii-protection-relay-replacement.696990/ I purchased a new protection relay and installed it. And the problem got better. No scratchiness, and everything seems fine for long playing periods. Then, suddenly, the same channel goes quiet. Not out, but very quiet. And now the volume "push-through" trick no longer fixes it. BUT, if I simply turn the unit off and then back on, it's fixed, at least for a good while... then gone again. Off-On, fixed. So it's gone from non-operational to annoying. My skills are very limited; I'm fairly proficient with soldering, so when there's a thorough explanation on here like the one in the thread above, I can handle the repair. But as far as real trouble-shooting on my own, I'm lost in the woods. Anything else that I can try, or do I just need to turn this thing over to an expert?