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-   -   Does anyone have experience of replacing a laser? (http://www.diyaudio.com/forums/digital-source/15751-does-anyone-have-experience-replacing-laser.html)

EC8010 28th May 2003 06:07 PM

Does anyone have experience of replacing a laser?
 
I have a Marantz CD63 (the original 1983 top-loading wind-up version) that can't read a TOC even after having its lens cleaned. Amazingly, I have a replacement laser assembly and digital chipset. I have some generic guidelines on laser replacement, and it doesn't look impossible, but it won't be a trivial job.

Does anyone have direct experience of this job? I would quite like to see this machine working again, even if it doesn't sound anywhere near as good as a CD63mkII (and it doesn't, I've heard them side by side).

Netlist 28th May 2003 06:31 PM

Re: Does anyone have experience of replacing a laser?
 
Quote:

Originally posted by EC8010
I have a Marantz CD63 (the original 1983 top-loading wind-up version) that can't read a TOC even after having its lens cleaned.

It's not certain that the problem is with the laser.
I will look for additional info, translate it and post it.

/Hugo ;)

Netlist 28th May 2003 06:55 PM

First possibility:
Clock-signal at pin 22 of demodulator is 6MHz, should be 4,35Mhz, pin 18 is then 9V, should be 5V. C2501 (22nF) is short circuit, which makes pin 16 to positive.
You will need a frequenciecounter.

The eye pattern is measurable at pin 7 of the same IC.

Second possibility:
IC 6504 is broken; data is at pin 2, 3, 11 and 12 should be 5Vpp instead of 1Vpp.

Third possibility:
Replace the laser. :devilr:

I have no service manual; IC6504 probably is the demodulator; as a result the first possibility should apply to that IC.

/Hugo maybe someone digs up a schematic for you. :nod:

EC8010 28th May 2003 07:00 PM

Wow! Thanks for that, Netlist. I can do all of that, measuring is no problem at all - I have a 300MHz oscilloscope.

Netlist 28th May 2003 08:16 PM

2 Attachment(s)
I all measures well, it could of course be the laser.
If it's a VAM1201 you can easily replace the whole unit.
It's utterly cheap, and easy to do.

/Hugo

EC8010 28th May 2003 09:47 PM

Apparently, it degraded gradually...
 
It's a long while since I took the covers off this machine (and I haven't yet had the opportunity), but the mechanics are considerably more agricultural than your image. As I remember, it's all die-cast aluminium, and very substantial. This is the first CD player...

ALW 28th May 2003 10:12 PM

CD63 service manual
 
If you visit this link in a while, the manual will be there for download - it's about 9Mb.

http://www.alw.audio.dsl.pipex.com/D...ice_Manual.pdf

Hope it helps - changing the mech is a trivial task, only takes a few minutes, but take care not to damage the flexible PCB interconnects and remember to take ESD precautions!

Andy.

P.S. the original mech was a CDM12.1, but the replacements are usually VAM1201.

When fitting the latter the disc clamp HAS to be replaced with one of the two supplied (1 for tray-loader, 1 for multichanger).

EC8010 28th May 2003 10:34 PM

ALW,

thanks for the manual. I will use it for my (much) later CD63.

However, the CD63 to which I refer is the much earlier clockwork top-loading version. It's the original CD player, and will probably soon be a museum piece!

jean-paul 28th May 2003 11:25 PM

Difficult eh, when everybody is speaking of something else ;)

I think you better have someone experienced changing that laser assembly. Don't know this particular Marantz but I guess it has CDM0 or CDM1 swingarm mechanics. CDM12 or the VAM are not applicable to this cdplayer ( thank God for that ).

Replacing the laser is difficult, replacing the whole mechanics is not hard. You also have to check eye pattern etc. on a scope and adjust potentiometers when necessary. If you decide to do it yourself please be aware that these lasers are very sensitive to static electricity. Leave the paperclip on the flex-PCB till it's built in the cdplayer and ground/earth yourself.

EC8010 28th May 2003 11:53 PM

Jean-Paul,

it's almost certainly an CDM0! Having read the generic guide, I knew that eye pattern would need to be optimised, and that the whole thing wouldn't be trivial. I was rather hoping that someone would come along and say, "the manuals tell you this, but the cheating way is to do this." I know that the laser current for IR output is critical, and I was rather hoping that someone might have a cheap and cheerful way of setting it. What with one thing and another, this doesn't look too hopeful. And yes, the packaging for the laser assembly is covered in antistatic warnings.


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