Laser surgery on CDM-x - Page 2 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th October 2004, 09:56 AM   #11
Thomas is offline Thomas  Denmark
diyAudio Member
 
Thomas's Avatar
 
Join Date: May 2001
Location: Right here
Thanks for the feedback all

Mr Boky: thanks for the advice. I am ordering the CDM service manuals today, and I have access to scopes at the school lab. They are closed for holliday this week thoug. I should get my own scope.

gmphadte:

The pictures was taken from the side. The small PCB to the right is the sensor array. The lens assembly is on the left. I believe the two-wire flexband going over there is for the focusing coil. You can see the coil at the first picture, by the way.
  Reply With Quote
Old 14th October 2004, 02:16 AM   #12
beomuse is offline beomuse  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Texas
Default ROHM Laser in CDM4

Hi! Our shop has used a few ROHM lasers in CDM4 with good results. The primary issue is indeed ESR and overtemp on the iron. It took a couple of tries until we got it right. We have 4 test units in the field with our client repairs. So far no complaints. CDM units prior to the 4 used the classic TLO22MC with the HUGE external body. We are awaiting a few adaptors from our micro-machinist in order to test on CDM0/1 and CDM2. CDM0/1 is rather tricky with the soft plastic insert and deep well along with no alignment pin! Using a jeweler's saw to cut into the well will allow a smooth removal of the laser.

anthony garza
beomuse.com
  Reply With Quote
Old 14th October 2004, 02:04 PM   #13
Thomas is offline Thomas  Denmark
diyAudio Member
 
Thomas's Avatar
 
Join Date: May 2001
Location: Right here
Good to hear from you, Anthony.

From your description, I almost can tell I ruined the laser as I used heat to soften the glue.

What type of diode do you use from ROHM?

I am ordering a few diodes from Roithner Laesertecnik, but they are difficult to talk with, I think. I have talked to them from for 4 days now, and no order. Maby I should try ROHM instead...

In the meantime, I ordered the service manuals I need from UltrAnalog and an oscilloscope from Helmut Singer without no problems.

For now, I'm practising on a allready gone CDM-4. My objective is to repair CDM-0 and CDM-1's. I can't get any info on the old diode, though. Also, I don't have any spare CDM-1's to practise on right now. I am very interested in hearing about the adaptor you are getting manufactured. Also, what kind of diode needed in pre CDM-4 pickups.

You can use my e-mail at myname@diyaudio.dk if you want. (my name is thomas )
  Reply With Quote
Old 14th October 2004, 05:23 PM   #14
diyAudio Member
 
Join Date: Jun 2003
Location: Wroclaw
Quote:
I will find out later this week, when I get my replacement diodes.
Where did you get the replacements? Are they specifically to CDM 4?
  Reply With Quote
Old 15th October 2004, 11:05 AM   #15
Thomas is offline Thomas  Denmark
diyAudio Member
 
Thomas's Avatar
 
Join Date: May 2001
Location: Right here
Quote:
Originally posted by zygibajt


Where did you get the replacements? Are they specifically to CDM 4?

Laserdiodes are 'generic', if I can put it that way. Only, they should have the same specs as mentioned in the service manual. The only consideration is the house type and if it's a P or N device. A normal CD player (not writers, dvd, etc.) use 5mW, 780nm, AlGaAs lasers.

As I mentioned, I have contacted Roithner, but I'm having troubble with them. I contacted them first time monday and they still hasn't sent my order. They have a price list online, so I asked for a quote for postage by e-mail. They answered quickly back. In the same mail they informed me that the laser was much cheaper than in the catalog. So, I answered back I would like to buy some more pieces, then. They didn't seem to understand, but wrote back, informing me they don't have any minimum order!!!

YES I KNOW THAT!!! I'M JUST ORDERING FIVE INSTEAD OF ONE!

Ofcourse I didn't wrote that. I wrote back and apologized for the misunderstanding explaining what I thourght was obvious, but we should get the order going now, please. Then, the person I was exchanging e-mails with handed over the 'case' to another person. She started out asking me if I was a company or private, because of 20% VAT. This was two days ago. This is okay by me, I just wrote my name (person name) and not a company name in all the other letters! This is taking too long for me. I just wanted them to give me the payment details so they can send the diodes. I'm thrugh with them. They are polite enough, but.... 5 days of dealing because of a few diodes 3,5 each is enough.

http://www.roithner-laser.com/index.htm

I'm about to find me a nice ROHM dealer instead.

At the same time this is going on, I have ordered a cd with service manuals from UltrAnalog (member here) and an oscilloscope from Helmut Singer Elektronik. Both deals was pleasant and quick. If I'm lucky, they are both in the mail tomorrow.
  Reply With Quote
Old 28th October 2004, 11:22 AM   #16
Thomas is offline Thomas  Denmark
diyAudio Member
 
Thomas's Avatar
 
Join Date: May 2001
Location: Right here
Hi again. Just a small update and some info.

I know the last post wasn't pretty and I'm sorry about that.

I have ordered a few ROHM lasers from an other supplier. In the meantime I'm working arround the hot milk like a cat. (That's an old danish expresion meaning I can't get to the center of the case regardless of trying.) While waiting, I have done some clever research, I got my own oscilloscope now and I bourght me some 'subjects' to try out my theories on. Last night I arbitrarly browsed into ebay and spotted no less than two good deals. One CD104, presumably in good condition. The other deal was for two half suspect 304's. They are sold by the same guy and both had the 'buy now' option for 25. So, three classic players for 50 he even ships them in the same package!!!

For lasers in CD players, three possibilities exist; M, P or N type. A laser for this application consists of two diodes, - a laser emiting diode and a photo diode which measures the output from the emiting diode. They are tied together with one common pin. They can both point in the same direction towards the common pin, or each one in the other direction. Am I talking nonsense? Then, look here: http://www.rohm.com/products/shortfo...er_index0.html

Well, basicly two types were used in various CDM's. In CDM-0 and CDM-1, both N and M types were used. CDM-0 and CDM-1 has the laser supply 'onboard' and the type can be identified on the transistor ind the laser supply (N or P type). The difference is therefore internal to the unit and units can be interchanged regardles of type. The laser is an old type with a different house than modern types. A new laser can be fitted, but an adaptor must be fabricated.

The CDM-2 manual states it was replaced by the CDM-4. They are more or less the same, with a few small differences. One of the differences addresses the laser diode. "nu niet meer geselecteerde laserdiodes" which I translates to "now no longer selected laser diodes". In other words: all drives uses the same type from now on (type M).

CDM-3 : No freakin' idea. The CDM-3 has the (hall effect) motor control onboard, but not the laser supply?? AS the laser supply sits in the player it self, all CDM-3 must use the same type in all cases in order to be interchangeable.

CDM4: All variants uses the M type.

CDM1 mkII: Not a improved 'mkI' from the early 80's but a retro style CDM made from CDM-4 parts. Therefore: M type.

CDM-9. I have absolutely no information on CDM-9 or any player using it. Since Philips dropped the idea of producing two types with almost nil differnces years ago, my guess is they are using the same type in all variants. If they had any leftovers from the CDM-4 production it would be M type.

CDM-12:
  Reply With Quote
Old 28th October 2004, 09:12 PM   #17
guido is offline guido  Netherlands
diyAudio Member
 
guido's Avatar
 
Join Date: Mar 2002
Location: diepe zuiden
Quote:
Originally posted by Thomas


CDM-3 : No freakin' idea. The CDM-3 has the (hall effect) motor control onboard, but not the laser supply?? AS the laser supply sits in the player it self, all CDM-3 must use the same type in all cases in order to be interchangeable.

CDM-3 is M type. There are at least two versions.
Best swingarm ever, but problems with quality. In other words, some outperformed CDM-0/1, some were worse.

Differences in the versions are in the hall motor!

Laser supply is indeed on the decoder pcb with standard stuff.

Look left and below
Attached Images
File Type: jpg cdm3.jpg (52.9 KB, 504 views)
__________________
GuidoB
  Reply With Quote
Old 4th November 2004, 04:18 PM   #18
Thomas is offline Thomas  Denmark
diyAudio Member
 
Thomas's Avatar
 
Join Date: May 2001
Location: Right here
Exelent info, thanks Guido.

Last bits arrived in the mail. Laserdiodes are very hard to find, I think. Maby I just looked all the wrong places. I managed to get 4 M-type diodes for experimentation. I have no hope of ever getting any N-type diodes. Availability of these seems to be next to nil. In the case of a negative-supply CDM-0/1/2, the supply board must be converted to positive.

Well, back to my CDM-4. The unit was not functioning properly when I took it to parts. Maby this has something to do with my bad results? I don't know how eye pattern looked before, because I didn't have a scope at that time. I soldered in a new LD. I did a terrible job ruining the flexprint too. I replaced several cm.'s of flexprint with thin copper wire. - not the optimal solution. I learned a great deal about the process though.

So far I haven't been able to get any eye pattern from the unit. Maby it was peeked and poked too much because of me trying for the first time and can't be repaired any more. I can see the small red dot in the lens when in service mode or play. The photo diodes all checked out when comaparing to a 'new' unit. each diode meassures just below 1500 ohm unpowered and a bit lower in-system.

I discovered the LD could be rocked a bit in the socket. This is because of small bits of old glue stil sitting on the edge. I cleaned out the glue, bu no result so far.

I have a long week-end to experiment some more. You will hear from me soon again.
  Reply With Quote
Old 29th April 2005, 01:42 PM   #19
Tomg is offline Tomg  United Kingdom
diyAudio Member
 
Join Date: Mar 2003
Location: England
Hi, sorry to bump an old thread but I was wondering if there was any update on this at all?

Also, do you have the CD80 manual in electronic form?

Thanks,

Tom
  Reply With Quote
Old 10th May 2005, 07:38 AM   #20
leohung is offline leohung  Hong Kong
diyAudio Member
 
Join Date: Nov 2003
Location: HK
Default Help ! Test PHILIPS Laser!!!!

I use ROHM LD IN PHILIPS CDM-4.19. but don't use.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yamaha Surgery jackinnj Everything Else 5 15th July 2009 05:12 PM
Your surgery and operating table jackinnj Everything Else 14 6th June 2006 09:03 AM
Spider surgery - anyone? Jorge Multi-Way 6 11th November 2005 09:11 PM
Pioneer DV-414 smt surgery help -- please!!! TrevorS Digital Source 3 18th January 2004 05:50 PM


New To Site? Need Help?

All times are GMT. The time now is 04:17 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2