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A couple of decades ago, I was a sales rep for laser-based measurement equipment. We in the business "knew" that the half-life of a laser diode was about nine years.
My Denon CD player is starting to falter, and I'm wondering whether I can presume (as I do now) that the laser is used up and it's time for a new one. Is this a process that anyone has gone through? I mean, many of you just use some of your lunch money to buy a new player, but I like this one and I hate to see all this hardware go into the dumpster just for a little bitty diode.
Informed comments and shared experiences anyone?
Thanky.
Follow Ups:
FIRST off........Clean the lens propely, its bound to need it.Jeff Medwin
Here is a post I found :
Old 4th February 2013, 09:39 AM #19
Mooly is offline Mooly United Kingdom
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Join Date: Sep 2007
Pleased you found it all usefulFirst thing has to be to clean the lens. It should look bright and shiny with a bluey tinge under a stong torch light. I know ISO (IPA) seems to get a universal recommend as a cleaner but its something I would never use on optics tbh. In the early days Sony even issued a warning to that affect saying that ISO could damage (the then newly introduced) "coated optics". Camera lens cleaner perhaps or just warm water with a single drop of detergent mixed in.
I doubt whether the sled is sticking tbh but that said you have to consider the possibilty. Monitoring the voltage across the sled motor in playback is a good clue. If it suddenly starts to rise its a good indication the sled has stuck. The voltage will keep rising until the motor overcomes the friction and the sled jerks forward.
Most likely is a faulty pickup. The KSS240 was notorious for giving trouble. A replacement should work straight off and is easy to fit.
___
Edits: 06/05/13
Well, it turns out that lasers for these machines are out of production, and the only ones available are second-hand, which would be just as old as the one that I have now.
So now I guess I'm shopping for a new player. Dammit.
Most stuff these days is built like that. Can't just replace one bad part -- have to replace the whole damn unit, probably with an "improved" model not as good as the original.
The lasers do have a finite life - and having purchased research units for instrument development - there is definitely a wide variety out there -
I would have thought that due to FCC regulations that the Laser in a CD player would have been downrated - or depowered to an extent such that the useful life would have been quite long indeed - however 20+ years is a long life and as has been said before - can't sell new ones till the old one stops working....
I guess I should start looking for a new player -
Happy listening
what laser mechanism your Denon uses ? I sold Harman Kardon which used a sony laser mechanism and I still have units in the field over 20 years old and still going strong, staill able to read CDR's and such.
One of the major issues with the CD players is that the laser lens is sort of like a camera,it has a difinite focal length. If your mechanism has a magnetic chuck, the constant opening and closing of the drwer nd the resultant slamming down of the clampiong mechanism tends to "hammer" the turntable dowm, and eventually it reaches the limit of the focal length. You will notice this first on the the data on the edges of the disc, where any eccentricities will be amplified.
Since the CD TT is simply friction mounted on the motor shaft, often times a gentle prying upward of the TT will place the surface of the CD back in the proper focal range.
good luck.
Stu
The service manual calls it a KSS-151A. A Sony device, perhaps?
That is definitely a Sony number. Most Sony lasers are easily replaceable.
That particular one unfortunately is obsolete and no longer available
is definitely Sony type part number.
Your original post was unclear about the issues you were having.Skipping, particularly at the outer edges of the disc? Can't read nurned disc?
Please elaborate a bit
Stu
Yeah, just like you said. It won't read a burned disc(that DiscSpeed says is 100% quality). I got some skips in the middle of a commercial disc but only once that so far.
Can you help me, doctor? I've got a cheap Sony machine with the same thing too...
Mush
Not too familiar with the 150 mechanism. Spent the night trying to locate a photo or replacement part with photos so I could see it and identify the mechanism
patience.....
Nt
the focusing servo motor is there for decoration, then. Oh well, another circuit needlessly added to add more cost to the consumer.
The servo acts like an auto focus so the laser doesn't a have a "definite focal length." I.e., it's variable.
mechanism has definite limits
Electrons just get old and tired I reckon. Sigh.
:-)
Actually what happens is that something in the device chemistry oxidizes over time. They'd stop it from happening if they can, but as far as I know nobody has said that they can do that yet.
This player is about 23 years old, so the timing would be about right.
Dunno, could be anything. Nothing lasts forever, geez, technology refreshes what, every five years? Do yourself a favor and get a new player.
Edits: 02/02/13
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