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The D100 has an issue, it's quite diffcult to read discs. It always needs a while to read TOC and begins to count on the screen. Even if it reads the disc, we can only hear severe noise from earphone (via both line out and eraphone out) with a little music mixed in. Since it can read TOC and play discs, I guess it might have something wrong with its DSP/DAC/Digital filter part. When I increased the laser power, the noise decreased a little bit and the music became cleaner. Therefore, I'm sure the electrical circuit is working well. The issue comes from its laser part.
I checked its RF pattern and found it's level was 0.6Vp-p on CDR. So I adjusted the RF to 0.8Vp-p, also the TB and FB. It still works like it used to be. I tuned the VCO, nothing happened. I found something wrong. Ordinary, if we have a clean RF wave and we count the grid on the oscilloscope's screen, we can have the level of the RF wave like 1.0Vp-p. But the oscilloscope will give a value with a little bigger number like 1.1Vp-p. It means the RF wave has some "burr". Although it's not the real RF signal, the oscilloscope counts it along with the real RF signal. The cleaner the RF sinal is, the smaller the difference will be.
In this situation, we can count the grids to know the available RF level is 0.8Vp-p; however, the oscilloscope says it's 1.77Vp-p! Why the D10 has so huge "burr"? I checked the screw connecting the PCB ground and metal frame, it's good. So, I might replace its laser for last try. When I flipped over the laser assembly, I found the cable conncting the laser upper metal cover with the PCB ground is already broken! When I soldered it with the ground, the player come back to life!
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Post time 2016-03-05 00:30:59
Post time 2016-03-09 08:01:15
Author
爱人332681713 
2016-12-28 07:30
,thank you ,kaosun