6808 hard to read the CD.

Gwent

Dear every one. My 6808 cannot ready cd smoothly. It can read some cd and almost CDs cannot read.. In some case, it can read the cd but have some skips or hard to jump to other tracks.
This is my video of my 6808's problem:
https://youtube.com/shorts/sVArj7iptPU?feature=share

First of all, I cleaned and services the mechanic of the optical part and use 3v dc to check the motor can move the laze out and in ok. (I already used services test in step 2 to check the lazer can move in and out smoothly)
After that I checked caps 2860-2861 in here


the result of
2860: 108uf vloss 0.3% esr 0.13Ohm
2861: 114.9uf vloss 0.2% esr 0.09 Ohm
I think these caps are ok.
After that I checked cap 2815 in here:

and that cap was: 24.6uf vloss 0.2% esr 0.19 Ohm
I think it's OK.
right now I dont know how to move on. Can anyone give me an advise to move on please? I will reply the result ASAP.
Thanks

kaosun

It seems it can read TOC but has difficulty to access tracks. Pls adjust RF by checking your oscilloscope. This model has no capacitors' issue. What is needs is careful adjustment of laser signal.

Gwent

kaosun replied at 2026-04-17 08:54
It seems it can read TOC but has difficulty to access tracks. Pls adjust RF by checking your oscillo ...

I'm new in Oscillo but you mean HF signal in 3838? I will try and let you know the result for it. In normal of Sony or other cdp I saw there is a [color=rgba(0, 0, 0, 0.87)]a variable resistor in lazer part to change the voltage go through lazer optical. But I dint see that in philips's.  I didnt see the part to measure the voltage go through optical in SM.

Gwent

I set up to measure HF as this pic

And this is my signal in my oscillator

(Sorry i dont know why these pic are rotated, in my phone they are not rotated)
I saw that vpp is about 1V when 6808 can read the cd, and it will not show a wave when cannot read the cd. Please help me to move on please??
This is myvideo when 6808 cannot read the track.

https://youtube.com/shorts/WniYDpBJo1s?si=NwykKdaEOweMLPXk
Thanks.