Sony DVP-9000ES + cd-r = Failure ?

[air]

I have searched a couple of forums, and some people state that this player does play certain brands of cd-r´s and some do not work. I was thinking about buying one of these players, since it is a good built nice looking, and hopefully great sounding player. Althoug, this cd-r problem seems to destroy lots of the good things about this player.

So heres the question, is there anyway to make this player support cd-r ? It uses the KHM-220AAA pickup. Does anyone know if the non-cd-r support is due to hardware or software problem ? Is it possible to fit another pickup that supports cd-r (if hardware is the problem) or to modify this one?

Service manual is available at: Link removed by mod

[jean-paul]

The link to the manual is removed as it seems the data at that site is unprotected. I was able to see and download various other official preliminary data on Sony gear, including presentations and other stuff like adjustment procedures and such. I tested the site at the normal entrance and found that some areas have been secured by password etc. but this does not work when traveling through directories.

Even worse there are cartloads of pics of naked women on that site which is not according forum rules

[air]

jean-paul: Sorry about that link. It is not my page, only a link to a service manual wich I found in a sony forum. (I believe it has also been on this forum is some other tread).

[jean-paul]

OK, air. I editted my post and sent a mail to the owner of the site.

[air]

Ok.

The question still remains, and anyone interested in the service manual can send me an e-mail.

[Extreme_Boky]

Hi air,

The problem is hardware related. The player reads some cd-r disks, so it should read them all if adjusted properly.

In my opinion, it is a disk reflectivity that causes the problem. Some disks have higher reflectivity, and some cd-r disks have very low reflectivity. This can be easily measured with an oscilloscope connected to RF test point (as I mentioned couple of times here already on Forums).

Laser diode output should be high enough, but not too high to shorten its life. There is another important factor: Vcc is +5V, so the eye – pattern (at RF test point) should be adjusted to 1.5 Vpp with low reflectivity disks. High reflectivity disks would reflect more light and increase this value to 1.8 – 1.9 volts, and this is a maximum in my opinion.

Find first the RF test point and measure / check the waveform. See if it is anything close to what I think it should be. Use any CD. Press play.

Then, insert a low reflectivity cd-r disk in to your player and with little trim-pot located on the pick-up, adjust RF pattern to 1.5 Vpp.

I am not 100% sure what’s the Vcc in your player – it might be 3V (or 3.3V)

Nick

[air]

Extreme_Boky: Thank you for your answer. However, reports are that this player support cd-rw but not cd-r. Is it not so, that cd-rw has even worse reflection than a cd-r ? This is the thing that is pointing out that it might be a software problem, however it would be great if it could be fixed in such a simple way.

I do not own this player at the moment, but I have been looking for one, if I could find a solution to this problem.

[jean-paul]

Compared to CD-ROM a CD-R reflects about 50 % depending on dye and brand. CD-RW only reflects about 25 % compared to CD-ROM.

[Extreme_Boky]

The mechanism in question is probably over - scan mechanism. It measures reflectivity of a disk and adjusts the laser diode output level accordingly. There are two settings:
1. NORMAL setting for CD and CD-R disks.
2. HIGH setting for CD-RW disks.
It is highly likely that NORMAL setting works for CD disks, but does not work for CD-R disks – needs to be tweaked up a bit!

Oscilloscope works wonders…