Philips cd782 Issue

[Krokotam_]

Bought this player , and it was runing fine . So i thought it can be better . Changed some capacitors . Changed outpud op-amps . Those changes where not enought , sooo leets improve this player clock . I have tried a simple reclocking with mn74hcuo04 aaand everything was great really , this made huge improvement . I have listened to the player for some hours and at some point most of the ic`s became hot not that hot to burn but hot anyway . On the other day i turned the player again start playing it but i have noticed some noise from it and turned it off . I thought that reclocking went wrong and restored this player to factory mode , but nothing . What i have noted is that this player spins to fast *yes i checked that it might be SAA7220 issue bought new one and repleced it but nothing changed . Also i can hear laser head is banging on the disk when it is starting . I have changed nearest spindle motor transistors but nothing . So what might be wrong ?

 

[Mike P]

I had a similar problem once with an Arcam alpha 5, the turntable motor was spinning crazy fast and out of control. The problem turned out to be a bad connection with the SAA7220 which at the time was mounted in an IC socket. My best suggestion would be to check all solder joints and connections are good around this chip. Good luck!

 

[Stabby]

Did you build a separate supply/regulator for the SAA7220 without a heat sink?

 

[Krokotam_]

Mike Thanks , i`ve alleready changed old SA7220 with new one ... so it is resoldered. Stabby no i was using existing one , and after this incident i have replaced it with new one just in case . I have similar player cd780 and i`m taking parts of it and using it on 782 , 780 one is in working order . So i have changed both player DF and 780 is working now . Also changed op amp on the servo motor.Trying to check TDA5709 , but no luck so far in measuring it .

 

[Mike P]

It's normal for the SAA7220 to get quite warm. Which other IC's got hot?

 

[Mike P]

Oh and did you make the mistake of using any very low ESR capacitors directly after voltage regulators?

 

[Krokotam_]

No no new capacitors so far . I have learned this lesson with Marantz cd60 I have changed 12 volt diodes with shotky but this was at the time when the player was working so i doubt that this can harm it .

 

[Stabby]

What lesson did you learn exactly from your Marantz CD60? I'm about to change the caps in one of my players...

 

[Krokotam_]

Stabby some times when using low esr caps you can provide more power to some ICs , this can destroy some of them , also more capacitance . But let`s stay to the topic I`m still unable to play anything on my cd .

 

[Krokotam_]

So far nothing found ... i`ve watched to the lens and saw that knocking is from it banging at the end of the track , strange .

 

[Krokotam_]

- servo - in red squares parts changed .

at the back of SAA7220:

Whole board :

Well today after replacing 5709 spindle motor stopped to rotate . As far as I am aware when reading disk must rotate , but at what point what ic is responsible for that i have no clue .
If someone has a decent user manual NOT ON Dutch i will be more than happy to see it Now i can see that there are significant differences on my board and the repair manual i`m using ...