Can't provoke it by heating things up with a hairdryer, nor by tapping the boards and connectors. And of course, now that the player sits on the bench, opened up and with the scope connected, the issue has not shown up over the past three hours. All at their nominal values, and nice and clean. (The mute relays are bridged, since I had suspected them to be flaky and cause the noise.) That would suggest that the problem lies further downstream, on the demodulator/decoder board, right? As suggested by LA7SJA, I have looked at the power rails again. When I have these things in front of me, I can usually figure it out in minutes, mostly by LISTENING to the player for the unique sounds it makes, but on forums it's really tough.Īs mentioned in the OP, I am confident that it is not the laser, tracking, or drive (fortunately!), since the noise also occurs while the player is sitting idle without playing a CD. You may have to try turning the bearing screw 1/4 turn clockwise if you have a CDM-1 to test if the spindle has worn a divet into it. This is often the case with Revox and Studer players as well. I have found that taking it apart and oiling it and then re-adjusting the spindle height properly can fix many "problems". The later one had a CDM-1 with the indestructible hall motor. The CDM-0 has a brush motor and is why I sold mine. I have fixed 1000's of philips based players. This can cause scratching sounds in the audio as well. I have ALSO observed the spindle motor being lazy. The player may need a touch up align on a scope. Really only scoping the RF Eye pattern will tell you. Although if it plays redbook cd's fine but has some trouble with CD-R's. Does it play a CD-R? If it does, it's NOT the laser. So you are good if you have a single sided board. Didn't even have part numbers on the laser and such. ![]() Mine had a ground plane, but it WAS a pre-production model. The "same time on both channels but different noise", as well as the fact that it also occurs in idle mode, seem quite characteristic - but I can't pinpoint the problem, and seem to be largely limited to trial-and-error since it is so sporadic. Or someone who has a creative idea where in the signal chain an error with the behaviour described above might lie.
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