TEAC VRDS T1 CD Transport

[hifiboy]

Hi,
I have a problem with the CMK4 VRDS transport mechanism of the TEAC VFDS T-1. When I insert a CD, the transport start to read the CD and finally goes back into the outer left parking position without playing the songs on the CD. In the handling manual it is stated that the laser will go in this position if the safety lock has been bridged. But I never touched the CD transport nor did I open the case! Does anybody of you know where to find the safety lock (is it a safety lock for the transport of the player
which is done otherwise with screws..?). And more importantly, does anybody of you know what is the matter with the CD transport? Does anybody of you still have the service manual for this transport mechanism? Thanks in advance for your comments. Any comments are appreciated!
Kind regards,
Hifiboy

[Adrian]

Does the disk spin?

I'm not sure about the safety lock. However I found that when the laser died, the mechanism tried to seek the disk but did not start the disk spinning and then returned immediately to the park position. I replaced the laser pickup and all was fine - mine uses a KSS240A available from most spares suppliers.

Looking at the manual, pin 5 on test point 1 is the output RF amp so should show something on a scope if the pickup is OK.

Adrian

[Guido Tent]

Hi

It looks like this is normal behaviour. Insert disc, close drawer. Machine starts reading, and displays the total disc time and # of tracks.

After that, it should start spinning again if you push "start", does it do so ?

regards

[hifiboy]

Thank you for your answer. I hope the laser is at least partly working. According to your statement, the transport must recognize that a CD has been inserted, because it accelerates it and the laser goes to the inner circles of the CD where the contents should be read. Could it be possible that the lens is simply dirty, so that the laser light is too weak for the sensor to receive reliable information? However, the display does not show any error.....

[hifiboy]

Hi Guido,

the diplay doesn't show number of tracs and total time! It remains dark! When I push start the CD doesn't spin. Therefore my doubt on the capability of producing sufficient laser light...

[Adrian]

If you turn the display on all the time does it show track 0 for all of this time - i.e. no error message. Draw closes, pickup moves to disk centre, disk spins up briefly, pickup moves back to park

I've just put a CD-RW in mine and it does exactly this. This shouldn't work (as the T1 can't read CD-RWs), but suggests this is what happens if it can't read the table of contents properly.

Does it do this for all CDs?

I would suggest cleaning of the laser. Its quite easy to do as it is exposed when in the parked position. (bit of alchol on a cotton bud). Following this, it is possible to adjust the pickup circuit using the trimmers on the main board, but I'm not sure I would recommend this. The manual suggests doing it with a test disk/scope and frequency generator.

Other question is whether the disk spins up to the right speed to read the table of contents. Not sure how you would know this other that looking to see if it spins at a reasonable speed.

Adrian

[Guido Tent]

Originally posted by hifiboy
Hi Guido,

the diplay doesn't show number of tracs and total time! It remains dark! When I push start the CD doesn't spin. Therefore my doubt on the capability of producing sufficient laser light...

Hi

You can measure the RF while it takes in the disc. I assume it is OK, and suspect that the Sony CDX2500 is defect

time to find a service centre.....

cheers

[hifiboy]

Hi,

yes, this happens with all the CDs. I think, that I have to check the disc speed and the RF signal. What is the function of the Sony CDX device?

Stefan

[hifiboy]

Cleaning the lens doesn't help... The error remains.

[Guido Tent]

Originally posted by hifiboy
Hi,

yes, this happens with all the CDs. I think, that I have to check the disc speed and the RF signal. What is the function of the Sony CDX device?

Stefan

Hi

Try to find if the rror is in the control domain or in the readout domain. If you measure RF when the T1 takes in the disc, you know that it can read discs, and that lenses and such are non-issue.

The CDX2500B is the decoder, but also gives back some status signals back to the uC circuit.

The datasheet can be found here

http://zorbacky.dyndns.org/zorbytronic/all/download.php

succes