Well, upgrading the transistor was probably unnecessary. I guess it didn't hurt. The only thing to watch for is that the replacement transistor beta is similar to the type you replaced it with. That assumes you're measuring beta. If it isn't, either select one that is, or use a different type that has similar beta. It's all a question of degree, but why make the servo chip work harder (run hotter inside). Remember that the dimensions of the internal drivers are much smaller than external transistors. The IC may not fail instantly or soon, but maybe before it would normally.
I never veer too far from the original design. Typically there isn't much headroom built into things these days. Not like the old days when everything was robust.
The KSS-150A had issues with melting the coils, the KSS-210A was the direct Sony replacement to solve that issue. You would see the plastic dust cover over the actuator melt. Impressive.
If the focus or tracking gains are too high, the coils will run warmer too. This is all common sense stuff.
I never veer too far from the original design. Typically there isn't much headroom built into things these days. Not like the old days when everything was robust.
The KSS-150A had issues with melting the coils, the KSS-210A was the direct Sony replacement to solve that issue. You would see the plastic dust cover over the actuator melt. Impressive.
If the focus or tracking gains are too high, the coils will run warmer too. This is all common sense stuff.
If I move it to the center, it returns to its reading position when I open and close the tray.This device was not used for a long time and the owner wants to bring it back to life, I found this to be the case, but I guess this behavior is not normal. The reading is perfect, even with burned CDs.As a peculiarity, I mention that it can read CDs with MP3, I don't know if that means anything😕
Hi @Mooly @anatech
I recover my old posts #357...#387 .
I've found the correct distance from laser and CD, and setted it.
And after lens and movements cleaning, now the laser works again !
But while playing the first tracks (1,2,3) the CD player produces a noise, like a 'beep-beep-beep' very quickly. It seems to be something mechanical (lens movement). It isn't on the audio channels, I can hear also at zero volume. It happens on different CDs.
Do you know where could be the problem ?
Other question: on service manual, at RF level checking, which track of CD YEDS-18 I have to play to show the correct RF waveform and the clearest 'eye' pattern?
Thank you
I recover my old posts #357...#387 .
I've found the correct distance from laser and CD, and setted it.
And after lens and movements cleaning, now the laser works again !
But while playing the first tracks (1,2,3) the CD player produces a noise, like a 'beep-beep-beep' very quickly. It seems to be something mechanical (lens movement). It isn't on the audio channels, I can hear also at zero volume. It happens on different CDs.
Do you know where could be the problem ?
Other question: on service manual, at RF level checking, which track of CD YEDS-18 I have to play to show the correct RF waveform and the clearest 'eye' pattern?
Thank you
Hi elpossa,
Could be your gains are too high, Focus and/or Tracking. Beyond that we would need to see it on our bench and look at servo signals with an oscilloscope. Go from there.
Find a CD with a clean eye pattern, the best one you have. Then carefully adjust the focus offset to make it clear.
Could be your gains are too high, Focus and/or Tracking. Beyond that we would need to see it on our bench and look at servo signals with an oscilloscope. Go from there.
Find a CD with a clean eye pattern, the best one you have. Then carefully adjust the focus offset to make it clear.
Make sure the disc runs true (no wobble if viewed edge on).
A good commercial CD with no surface marks should be fine for checking the RF pattern. Try two or three and they should all be very similar in amplitude. The RF looks the same on any disc regardless of content.
A good commercial CD with no surface marks should be fine for checking the RF pattern. Try two or three and they should all be very similar in amplitude. The RF looks the same on any disc regardless of content.