CDM1 laser

[FaZ72]

Hello,

I've just bought a Grundig CD7550 (CDM1) with broken laser. This player should be equivalent to the Philips CD303. To what should i pay attention if i want to buy another player with a usable laser?
As i've noticed that there are a lot of Philips cd104's (also CDM1) for sale here in Holland for good prices. Are the lasers interchangeble?

Regards,
Fabio

[poynton]

Originally posted by FaZ72


Are the lasers interchangeble?

Hi.

Yes, the lasers can be interchanged.

Andy

[FaZ72]

Originally posted by poynton


Hi.

Yes, the lasers can be interchanged.

Andy

Thank you Poynton. What about the laser of just recenter or earlier models as CDM0 or CDM2? I have a perfectly working Philips CD160 with CDM2 at home.

Regards,
Fabio

[poynton]

Hi.

The cdm0 is similar but not so common. I am not sure if it can be interchanged but I think not.

The CDM2 is different.

Andy

[phimor]

Hi,
I have successfully exchanged CDM0 with CDM1 (the whole mechanism, motor and laser). This was on a CD200 and Meridian CDM. In this instance I was lucky the plugs where identical. You will probably find later CDM1, as found in Philips 104's have later generation plugs for the looms, and are not a straight fit.

I believe they can be electrically identical, but the connectors are just plain incompatible. (An yes, the early servo board will drive the hall effect motor OK).

BTW, I seriously doubt the laser is broken on the Grundig, my experience is that other things fail before the laser.

Best way is to physically observe the laser spot on the lense at start up, but you'l need to partially dismantle the player, and certainly defeat the 'open door' interconnect on the laser feed.

There are many earlier posts that can help you there.

Good luck

Philippe

[FaZ72]

Originally posted by phimor
Hi,
I have successfully exchanged CDM0 with CDM1 (the whole mechanism, motor and laser). You will probably find later CDM1, as found in Philips 104's have later generation plugs for the looms, and are not a straight fit.

BTW, I seriously doubt the laser is broken on the Grundig, my experience is that other things fail before the laser.

Best way is to physically observe the laser spot on the lense at start up, but you'l need to partially dismantle the player, and certainly defeat the 'open door' interconnect on the laser feed.

Thank you Phimor.
Changing components in a Grundig player is a not an option, since the vallue of this players is in not changing even the smallest details!

I've won the player on ebay, and all i know for now is that it slowly stoped reading disks, until it didn't recognise any at all.

Is there a good change to repair the player without exchanging the transport?

Regards,
Fabio

[PetrL]

phimor,

regarding CDM1, I have one which is working, but far from perfect. If it recognises a disk, it still makes such a whistling noise when playing. Do you think it can be repaired? I already repaired supossedly dead CDM2 just by blindly changing electrolytics in the whole player, and readjusting. In the CDM1 I changed caps on the CDM chassis and in the whole PSU. But now, seeing no improvement, I'm in doubt if it makes sense to proceed with other caps.

[phimor]

Come on guys, the search function is your friend here ;-)



Fabio - I’m not sure what you mean by changing components not being cost effective, as capacitors (33 and 22uf typically) are not expensive. If you are considering changing a transport, ‘refreshing’ the caps is small bier.



Also if the Grundig is anything like a 303, then it’s a great machine, with that fancy loading tray/drawer, like the Marantz 73. Very solid construction. I like it a lot. Have a look at my other post on “TDA1540 – less is more”. Just because it is not valued by modders does not make it a lesser machine, the build quality is there.



Petri - For the soft ringing sound, my guess that it’s the focus gain, (the middle potentiometer on the transport board). Try adjusting it in small increments when the player is playing, and see if it can ‘go away’.



Do not play with the laser gain, especially when the diode is switched on. If you have no measuring equipment (oscilloscope) it’s potentially lethal for the laser to adjust the thing blindly.



Take care
Philippe

[palucca]

dear Fabio

the grundig 7550 is the same as the Philips CD304 ( without the headphone amp and remote function ) You are sure, that the laser is broken. Its posible to check the laservoltage with a digital voltagemeter. There are 575mV on the transistor.

Rüdiger

[palucca]

here is the picture...