Topic: player broke down

[ditterdi]

Hi,

I brought a Cyberhome DVD player from Europe. Cyberhome is an OEM product from China mainland, what you might call a generic player.
My wife bought a Mpeg4 DVD with 1000+ karaoke videos. It took the player a few minutes (!) to load the disk, after that it played the files.
When we got out the disk the player was gone. It does not recognise any disk anymore, it calls all disks "bad disk", DVD's, audio disks, VCD's, MP3 disks, JPEG disks ect all are bad disks. It also refused to read the firmware disk.
The technician at the repair shop says the motherboard has gone. Since the player was made for the European market I can not buy a new board here in the Philippines.
Does anybody know how a disk can destroy a board?

Leo.

[John E.]

the answers to this may seem very interesting

...let's wait and see.

[ditterdi]

nobody has a sugestion?

Leo.

[John E.]

and still...waiting...

[rascal101]

I don't know how the disk drive can destroy the board. How about cleaning the lenses? Did the technician do that? There normally is 2 - 3 pots that the technician can adjust assuming the lens are clean. The adjustments are as follows:

1.   Focus - F.G. (focus gain), F.O. (focus offset)

2,3. Tracking - T.G. (tracking gain), T.O. (tracking offset), maybe others.

4.   Spindle PLL, PLL adj., Speed, or something like that.

DO NOT TOUCH THE LASER POWER ADJUSTMENT - you can possibly ruin the laser if you turn it up too high.  Sometimes, just turning it with power applied can destroy the laser diode due to a noisy potentiometer.  This adjustment can only be made properly with the service manual.  It may require an optical power meter to set laser output.  Very often the adjustment is on the optical pickup itself so it should be easy to avoid.  Sometimes it is on the main PCB. The laser optical power output is feedback controlled and unlikely to change unless the laser is defective - in which case adjustments will have little
effect anyway.  If you run out of options, see the section: "Laser power adjustment" - last.

DO NOT JUST GO AND TWEAK WILDLY. You will never be able to get back to a point where the disc will even be recognized (without test equipment and probably a service manual).

First, somehow mark the EXACT positions of each control.  Some of these may require quite precise setting - a 1/16 of a turn could be critical, especially for the offset adjustments.

Sometimes, there will be marked test points, but even then the exact procedure is probably model dependent.

[ditterdi]

Hi,

Thanks for your sugestion. The lens is clean. I dont think the technician has the tools needed to make the adjustments you sugest. And the service manual for an european model dvd player is not avalable here.
My initial guess was that the verry long file list on the disk messed up with the firmware in the flash memory. But I do not know if that is possible.

Leo.