[osaca78]

Hello Dillen

I haven’t been able to determine whether the laser goes up or down. On the other hand, the head does not move and will not read the TOC on the CD.

I checked the condition of the flexible cable that powers the laser, it’s good, there is no cut

If the laser head does not move on the disc, does that mean the laser is dead?

 

[osaca78]

Hello Martin

To start the repair I had already replaced the C2103 cap on the servo board. (it is indeed a Philips axial blue,) because this problem is known and frequent on the Beocenter 9000/9500.

But the problem stay

It’s the reason why I replaced all the caps on the servo et decoding boards, but unfortunately the problem doesn’t solved and now I don’t know what To do know

[osaca78]

Yes, the Pin 21 to ground which bugged the bus and prevented the 4044s from operating normally

[osaca78]

Finally, the problem comes of the MM5450 on lower panel . After changed , it’s OK

Regards

Stephane

[osaca78]

Hi Spassmaker

If I switch on with the remote , only remote buttons work and LED are OK but the sensor buttons don’t work

I will make the Test mode wednesday because not at home Tuesday
Thanks for your helping !

Regards

[osaca78]

Hello,
I checked all the points mentioned
Here is the result of the checks

5 Volt on board 42 IC1 , 2, 3, 4 (5V clean =>no noise)

CLP signal seems OK: square signal but in the form of a “frame” no continuous signal => is this normal? => see picture Clock signal

Connection between P52-3 (Board 40) to P63-10 on board 42: OK

Check connection for Disp.Data from board 40 P52-2 to board 42 P63-11. to IC 3 Pin 22 : See picture (1)

Check Key Enable from board 40 P52-6 to board 42 P63-7: see picture (2)

Connection between board 40 IC 1 Pin 5, 6, 7, 8 via P52- 7, 8,9,10 to board 42 P63- 3, 4, 5, 6 to IC4 Pin 1, 9, 10, 13. : see picture (3)

Check 5 volt IC 4 on Pin 16: OK

[osaca78]

Hello

Thank you Spassmaker for this very precise technical informations
I will check it all !
Yes the MM5450 manages the LEDs but as the clock signal (pin 21) is also sent to the S/ inputs of IC1, 2 4 and I did not know what I had to find as a signal, it is thanks to the MM5450 datasheet that i now know what i need to find on this wire (500khz)

[osaca78]

Hello

According to the MM5450 datasheet, it seems that the signal sent to pin 21 (clock) must be 5V at 500Khz.
Can someone confirm these values by measuring on their BOCENTER 9500?

[osaca78]

Die_Bogener wrote:

It is possible to remove the glass panel … 1 bolt on the side. It’s a push and lift construktion… … and then you see the rubber contact to the glass panel. Or is it missing? Touch and start. Never touch the glass inside… NEVER!

Thank you Die Bogener , but the problem comes from the electronic circuits which manage the sensitive contacts.
I have already removed the glass and everything is OK at this level.

Regards

[osaca78]

Thank you for your quick response

Yes, I know this problem with glasses, but this is an electronic problem.

I removed the glass the one that allows me to touch the plastic tips directly with my finger, but no effect!

I did some measurements on the PCB 5V and 7V are OK. The integrated circuits are powered =>OK The fault being on the 3 PCBs (left, middle, right), I noticed on the electronic diagram that there was a common wire to the 3 PCBs. It is the wire marked I28 which supplies the 4 circuits IC1 IC2 IC3 IC4 on the “S” input of the CD4044 and MM5450. But I have no idea on which logic level (+5V or 0v I should find) Any idea?

[Author]

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