kaosun Publish time 2016-02-19 23:09:13

You just need to replace a few aging and leaking caps around CXA1271 and clean the leaking on the PCB, also repair the corroded circuit. By monitoring the oscilloscope, you can get best RF pattern by adjusting TB and FB. The RF waveform in your oscilloscope is weird... Pls check my latest Toshiba P22 post to compare my RF pattern in my Tektronix. But your amplitude seems big enough. Again, CDR 0.8Vp-p and commercial discs 1.2Vp-p.

Did you check the main spindle motor? It's better to lubricate both ends bearings. Of course, a bottom hole is necessary.

serge1996 Publish time 2016-02-20 00:20:18

When this board is transplanted into working DCP-50/150 I am getting the same thing: blurry "eye-pattern" which fails to snap into focus. So the problem is with the board, and I have already recapped it. Weird...

kaosun Publish time 2016-02-20 16:02:23

Did you clean the PCB underneath the leaking caps? It's necessary.

serge1996 Publish time 2016-02-21 00:56:37

will desolder that one leaking cap (red dot cap on the photo) tomorrow to check maybe I missed some damage. But yes, I clean board w/alcohol (my favorite step!), always ;-)
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