[Garten47]

Thanks Martin, Very possible,.but from its known history and looks inside it was fairly untouched, and its beoparts kit i used to recap 🙂 so should be fine…measured both current to the radial servo over the 4.70ohm R3160 and the current to the laser diode, everything looks ok and measure normal between outer and inner tracks. Still these oscillations that makes the radial servo coils “sing” at about 5khz… thinking of supresssing with a small 1nF cap on the L272 opamp output as i cant find the cause, perhaps cure the symptoms… seems unlikely its the motorcoils, but admit im unsure…i have a Philips cd-160 with the same servoboard, not sure its advisable to swap as a test…

[Garten47]

It was not heat dependent, I was mistaken, i measured the frequency its spot on 5168Hz, all the time….

Does this bare any significance?

 

thanks

[Garten47]

…After some additional analysis, there seems to be a heat/time component.

When the player has been switched on and playing “for a while” the high pitched noise goes away playing those end of disc tracks.

I also lifted the player and gently angled it in different tilts, that did not lessen, change or remove the squealing.

so something heats up and expands? or something heats up and becomes less viscous?

Thanks!

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