Spinning error

[George Kubitsch]

Help needed
My multiplay Pioneer PD-TM1 CDplayer ( used as transport) has failed during a listening session.
After about one hour listening ( in random play) I have
just noticed that the player is continously changing the
disks without playing anything. It seemed to me, that
the CDP does not sense if there is or not a disk in his drawer. Opening the case the voltages seems to be
good (+5V,+15V,-15V), but the disks are changed one after another without spinning them.
I made a try: on the PCB I pulled out the foil cable going from CXA1372S (SSP) to the laser unit (in power off state) and the player shows exactly the same operation.
So my suspicion, that the unit does not sense the presence of disks seems to be true.
How to go on?
Unfortunatly I have no service manual or circuit diagram
of the PD-TM1, and could not find any on the net, only a
SONY datasheet about of CXD2500BQ. This datasheet has an application circuit using CXD2500 together with
the CXA1372S Signal servo processor. These chips are used in my CDP too.
I finished my first DAC one month ago, and now I have no trasport.
I would appreciate very much any proposal or idea what to do next to repair it.
George

[sikkek]

Chances are the laser assembly is kaputt. In my marantz player, discs also did not spin up, the machine never got the 'Focus OK' signal. I replaced the laser assembly ($12) and everything is fine again.
You could also try to increase the power of the laser, but most of the times this does not help, or only helps for a short time (If the fault is not the laser, this procedure will likely ruin your laser, so try it at your own risk!!!!)

[carlosfm]

First thing to try is to clean the laser .
Have you done this?

[George Kubitsch]

Hi Sikkek, Carlosfm,
Thanks for responses, I will try to clean the laser and after that measure on Focus OK. I am sceptic about dirty laser , it has failed so abrubtly, and the laser unit looks down in my player.
George

[guido]

You can see if the laser still works: look at it at an angle in a nearly dark room: you see an orange circel on the edge of the lens.

DO NOT LOOK STRAIGHT INTO THE LENS. You will not see the orange glow, heck you will not see much 4ever!! (don't exactly know how bad it is, but i am not willing to try it out).

If it does, it could still mean that the receiving diodes (?) are broken or the electronics behind it.

The above procedure is at your own risk!

Regards,
GuidoB.

[George Kubitsch]

Hi all,
Yesterday I tried to clean the lens, but I have not found it on his place on the laser unit. I have mentioned earlier that the laser unit looks down in this player, and the lens dropped down to the under side of the case. I glued it back and the player works fine now.

Putting the parts together I have found another weak point of the player: the flat cable from the laser unit is connected to the PCB by a mehcanical (hand) operated
connector pressing the pins against the soldered ends of the cable. Depending from the pressing force ( the pins
have created holes in the soldered ends) the player shows a wide scale in the operation:
track locking error- only the rhytm can sensed- music with very high distorsion- good operation.
I have put there a light rubber to tense the cable to the pins for a temporaly solution.

Does anybody have a better solution to this problem?
change of connector, resoldering the ends of he cable...
Thanks
George

[Netlist]

Resoldering a flatcable is not an option. The heat will destroy it.
Buy a new one.

/Hugo

[peranders]

I have also a weird (before I knew) spinning problem with my Denon DCD-1520. My problem is weak laser (by age), too expensive to replace.

[Netlist]

Originally posted by peranders
too expensive to replace.

It's not that expensive, about € 75. Of course there are cheaper lasers.

/Hugo

[peranders]

If it was only the laser diode itself...... but I have to replace a rather big part which is over priced.