Sony CD player CDP-XE500 repair, bad Servo-DSP IC CXD2545Q

[Chungalin]

This nice Sony CD player based on KSS-213B optical pickup doesn't read any disc. Symptom is different from typical bad laser or dirty optics. It spins a bit and then it slows down while the lens is still focusing. Difficult to describe in words. Focus system has a characteristic sound that you can recognize when experienced.

I tried pickup in another player and, as expected, it worked fine. A new pickup replacement doesn't improve either. FFC OK. Check CD board SMD caps and C117 (100uF/4V) show 13Ω ESR. Replace it and no changes!

I recall that 10 years ago I failed repairing a Sony CDP-213, with apparently similar symptoms. I remember it because I've repaired hundreds of Sony CD players and they're all highly repairable. Check schematics and both share same CD board. Since I have them, I decide to replace main ICs (IC103 CXA1821M RF amp, and IC101 CXD2545Q Servo+DSP). First one is easier, I start with this one, no changes. Then IC101, and it's fixed!

[Xenon-Codex]

I saved a CDP-XE320 from the dump. It plays all discs, but with CD-R's it's hunting hard and then recognizes the disc. No hunting with most silver cd's. Can the IC101 cause that?

[Chungalin]

I don't think so. The failure I described was an all-or-nothing one, not a selective one like you say. I'd point to laser pickup, possibly dirty or dusty.

[stj]

ajust the laser current while scoping the eye pattern.
cdr's have lower reflective signal than pressed disks and cdrw's are even worse.
a lot of players - specially made by philips run the laser at minimal current to give it a long life - downside is they hate cdr's

[Xenon-Codex]

I already cleaned the laser. No change. It hunts 1-4 seconds to read the TOC, and then play flawlessly.