How to make correct adjustment of CDM4

Tubeee · 29th November 2003, 06:25 PM

Hi all pro,

There are two vars(potmeter) combo with CDM-4 laser pickup system (on the pcb beneath the CDM-4), 4K7 and 22K. As I know these VARs are for the adjustment of laserdiode output and focus.

Questions are:

How to make precisely adjustment. Does anyone has related service manual?

If I change a new CDM-4, do I need to re-adjust these var to a correct value? (I think my CDM4/19 is dying)

need your kindly help....

Cobra2 · 30th November 2003, 12:17 AM

Having nothing better to do(?), I took the old laser out of my CD-16 (CMD4-d36) and swapped the internals(laser) from a new CDM4.19.

Only the platter-motor differs (exept the metal...)

And everything works well, playing now...

Arne K

Tubeee · 30th November 2003, 02:47 AM

Hello Rudolf Broertjes,

I just search your previous post:
http://www.diyaudio.com/forums/showt...456#post120456

I think that's what I want to know now:

Quote:

I have the adjustement procedure for tracking & focus with the two test points (50mV and 400mV).

Where is these two test points: (or which registors?)
50mV is for tracking (laserdiode output)
400mV is for focus.

Is this done by using amp-volt meter to measure specific registor and check the amp cross it?

thanks

zygibajt · 20th November 2004, 10:15 AM

Hi,
Any one knows where the test points for this 50mA and 400mA are?

I got the CD-player where someone turned two trimming pots all the way up!

Bartek

Cobra2 · 20th November 2004, 11:11 AM

I guess it will be on different location in different players...
What make & model?

Arne K

zygibajt · 20th November 2004, 11:44 AM

There are always 22K and 4,7K pots and all the chips are usually the same.

The model in question is Marantz CD 883 but I have a couple of other ,diffrent machines and with CDM4/19 laser/drive it's always the same.

In fact this Marantz CD 883 is identical inside to the Marantz CD 65MKII ,just the same main board.

I have similar procedure for CDM 2/10.It goes ..."measure acros this resistor near that chip...and so on"

I need similar procedure for CDM 4/19

Bartek

Bricolo · 20th November 2004, 02:14 PM

Is the procedure the same for all CDM4 based machines?

zygibajt · 20th November 2004, 03:07 PM

Quote:

Is the procedure the same for all CDM4 based machines?

I suppose it is.Chips and topologies are the same.

If any one knows it please share it with me.

Bartek

rbroer · 22nd November 2004, 08:13 AM

Here you are

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

Designators can/will differ between several versions.

Just look for similar valued resistors on the pcb;
Many old Philips players can be measured near top left of transport.

zygibajt · 22nd November 2004, 11:44 AM

Many thanks Rudolf

29th November 2003, 06:25 PM	#1
Tubeee diyAudio Member Join Date: Jun 2003	How to make correct adjustment of CDM4 Hi all pro, There are two vars(potmeter) combo with CDM-4 laser pickup system (on the pcb beneath the CDM-4), 4K7 and 22K. As I know these VARs are for the adjustment of laserdiode output and focus. Questions are: How to make precisely adjustment. Does anyone has related service manual? If I change a new CDM-4, do I need to re-adjust these var to a correct value? (I think my CDM4/19 is dying) need your kindly help....

30th November 2003, 12:17 AM	#2
Cobra2 DIY ! diyAudio Member Join Date: Apr 2002 Location: Stavanger, Norway	What a hardcore diy'er do on a rainy saturday-night: Having nothing better to do(?), I took the old laser out of my CD-16 (CMD4-d36) and swapped the internals(laser) from a new CDM4.19. Only the platter-motor differs (exept the metal...) And everything works well, playing now... Arne K Attached Thumbnails __________________ Don't believe everything you think...

20th November 2004, 11:11 AM	#5
Cobra2 DIY ! diyAudio Member Join Date: Apr 2002 Location: Stavanger, Norway	Adjustments I guess it will be on different location in different players... What make & model? Arne K __________________ Don't believe everything you think...

20th November 2004, 02:14 PM	#7
Bricolo diyAudio Member Join Date: Nov 2002 Location: Grenoble, FR	Is the procedure the same for all CDM4 based machines? __________________ Just remember: in theory there's no difference between theory and practice. But in practice it usually is quite a bit difference... Bob Pease

22nd November 2004, 08:13 AM	#9
rbroer diyAudio Member Join Date: Mar 2002 Location: Netherlands	Here you are An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this. An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this. Designators can/will differ between several versions. Just look for similar valued resistors on the pcb; Many old Philips players can be measured near top left of transport. __________________ Rudolf Broertjes


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20th November 2004, 10:15 AM	#4
zygibajt diyAudio Member Join Date: Jun 2003 Location: Wroclaw	Hi, Any one knows where the test points for this 50mA and 400mA are? I got the CD-player where someone turned two trimming pots all the way up! Bartek

20th November 2004, 11:44 AM	#6
zygibajt diyAudio Member Join Date: Jun 2003 Location: Wroclaw	There are always 22K and 4,7K pots and all the chips are usually the same. The model in question is Marantz CD 883 but I have a couple of other ,diffrent machines and with CDM4/19 laser/drive it's always the same. In fact this Marantz CD 883 is identical inside to the Marantz CD 65MKII ,just the same main board. I have similar procedure for CDM 2/10.It goes ..."measure acros this resistor near that chip...and so on" I need similar procedure for CDM 4/19 Bartek

22nd November 2004, 11:44 AM	#10
zygibajt diyAudio Member Join Date: Jun 2003 Location: Wroclaw	Many thanks Rudolf

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