CD 104 repair and refurbisch

CD 104 Repair job, has been to 3 other repair shops , but still won’t work.

• Won’t read cd’s
• Disc spinning backwards

With original box

It has been recapped

Ground point for measurements 🙂

Axial caps replaced witch Axial , only 1 is wrong way around C 2266

 

4,7 µF replaced by  Wima 3,3 uF missing 1,5 uf ?!, also spindle motor transistors have been replaced

Aha here extra 1 µF 🙂

Removed Caps and repair griplets , working progress

Aha , there has been a short

Hmm cut wire…

Tested Photodiode detectors in service mode

Found a faulty LM339 that is used in start up of CD player

 

After Replacing the LM 339 , there is a nice Eyepattern .

There is still a problem , sometimes the player loses track, testing with servoboard from an other CD104 and the player is working fine.

The bad board has a non working wobble generator. 650 Hz sinus on point 45 is missing

Bad capicitor 5n6 is now 1,2 Ohm 🙂