Hello all,
Amidst other junk, I received a Sony HMC-695, which is an integrated mini stereo system. The three-disc cd changer wasn't working at all, always said "no disc" and didn't even try to spin up. I'm told it developed this problem suddenly. It seems that the cd player is contained on a small board beneath the turntable, and the motherboard just sends it commands and receives audio from it. The pickup has an octagonal black shield which is held in place by clips. I forgot to note the pickup model, but it looked a lot like this:
Cleaning the lens helped a bit: focus locks, disc spins up a bit and the pickup tries its best to move past the inner track. There are three adjustments on the board, which I've guessed to be focus, tracking balance and (tracking?) gain. Adjusting tracking balance (quite a bit from where it was originally), I was able to get the pickup to stay still, but there's still no tracking and no TOC. I just hear the wibbly-wobbly servo noise that Pioneers make with only focus and CLV servos enabled. The disc appears to spin at about the right speed, though it varies a bit.
While I was playing around with the adjustments, I got the TOC a couple of times and once it even sort of played (didn't have speakers connected, but the eq-like display had its bars moving up and down). I must've hit the wrong place with my screwdriver.
So. Something must have failed in the tracking circuit, but what? Or could the optics just be dirty? The behaviour seemed the same on pressed and CD-R discs, so I don't really think so. I can't figure it out and it's too late at night anyway...
br, Ilkka