Sunday, October 24, 2010

Sony XC995 Repaired!

After tracing the spindle driver electronics, I determined that the controller was not even attempting to spin the DVD for some reason. That reason must exist somewhere earlier in the disk reading algorithm. Now I was starting to fear I would have to replace the whole DBU-3 optical assembly, available for about $99 on ebay.

I tried to re-calibrate the drive through the diagnostic tools built into the player (press Edit-Clear-Power in sequence while in standby). The calibration required loading a single layer DVD, audio CD, and a dual layer DVD. The calibration utility did not seem to help. No DVDs would even spin up. However, the audio CD I loaded for calibration started to play! So clearly, the hardware detecting the media type even before spinning it up. For some reason focus on DVDs was not possible. In retrospect this makes a lot of sense - it is probably much easier to focus on a non-moving target. Failure to find focus would result in the drive rejecting the disk.

Next time I loaded a DVD up, I pulled the disk a short distance away from the lens by sticking my finger inside the drive. I saw the lens focus and the spindle started up! Of course, it would not work with my finger sticking in there, but this was an excellent sign!

Now, in my initial attempt to debug this I had removed the spindle motor. This involved removing the plastic hub from the spindle shaft. Upon re-assembly I pressed the spindle hub on to approximately the same location as I found it. It turns out that the original hub installation had likely been pressed on a hair too much. Perhaps after a 1000 CD loads, and a bit of mechanical wear, DVDs started to be loaded just outside of the focus range of the optical system.

The repair was simply removing the spindle hub and re-installing with about 1/8" of clearance. Now everything is working!

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