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Hello,
I'm trying to repair a D-211 I bought as "defective". Initially it did not read discs. Just a series of klack-sounds from the pickup until it gives up and turns off. When observing it during focus search it did not move up and down smoothly but seemed to go downwards in two jerking motions, eventually bottoming out and making the sound, then moving back up smoothly. Adjustments to FG/FB did not change anything. In my experience a lens that bottoms out needs those adjusted, not here. In TEST mode with focus search turned on the lens would move up and down smoothly, so it's not a mechanical problem.
One thing that seems strange is that the cover plate of the pickup looks crooked compared to the rest of the drive, hmm. Also before adjusting the pots I always measure them, but I had issues with RV503 FB. Measures ~1.3K across but from the tap to either side is like 200K, seems there are some capacitors in the circuit preventing accurate resistance measurements for this pot. Ah well, not sure if any of this means anything.
Spindle is pretty busted, cracked / unattached retainer on the hub. Glued it back together, disc sits at the right height and doesn't oscillate much. I can replace the spindle if I get the player fully running.
The SMD electrolytic capacitors seemed shot, measured poorly, many where just open circuit. I replaced them all. Did not have 33uF with the correct footprint, used 47uF for those. Measured all replacement caps with an ESR meter beforehand, seemed fine. Checked pads, traces and adjacent vias for damage, found none. PCB is still in good condition as far as I can tell.
After recapping and some adjustments I got the player to reluctantly read the ToC and start playback. A few klack sounds from the pickup and it would read the ToC and after a few more klacks there's a chance it starts playback of track 1.
Once the player starts playback it works perfectly. Plays the entire CD with no glitches, perfect audio, all buttons / functions etc. work, everything fine. Even returns back to Track 1 with REPEAT on, no delay. It runs somewhat noisy and skips with a light touch, though. Sounds are coming from the pickup servos, I assume. As soon as I seek or skip tracks it gets stuck in the klack-klack-klack loop again and needs like 10-30s to resume, sometimes just gives up.
Interestingly, after letting the player sit for a few days it stopped reading discs at all. I had this happen before where after a recap and adjustment a player kinda, sorta worked and then a few days later it was completely dead again. 1min of playing with the FB and it's back to the prior state of reluctantly working. Two days later, same thing.
I adjusted the laser power pot from 1.116K to 0.909K, that's where improvement started to level off. Player now takes a bit less time to seek this way and works more reliably. Can play all CDs and go to most tracks, just takes a long time to seek. When switching distant tracks the pickup seems to move to its destination in tiny increments (not a mechanical issue). When using the RESUME feature of the player, playback starts immediately where it left off.
Next day, player barely reads discs anymore, would probably need to adjust it all over again.Why does this keep happening where I get it to almost working state just for it to stop working again the next day? Why does the player have such a hard time to get playback started but then works absolutely perfectly and plays for hours on repeat once started?
Any advice on how to fix this would be much appreciated!!
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