Denon DCD 1520 not recognise some disc

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
15 years old Denon DCD 1520 CD player refuses to play some discs. Has been a continuing problem for 10 years but getting worse - can't read more and more discs!
Service agent in distributor here (Sydney) offered to replace laser pick up assembly KSS-151A (Sony?) but did not guarantee outcome. I knocked back the offer.
Reading up some material on the net, I started to open up the machine. Found that for 'playable' discs, the motor spins the disc clockwise and reads the directory track. For 'unrecognised' disc, it actually spins it anti-clockwise for about a revolution or so, stops with a click sound, tries again for a few times, and displays 0's on the front panel.
I have tried cleaning the lens, no results.
Would anyone please tell me what's wrong?
 
Thanks, Stephensank.
The price for Denon's local agent to replace the laser assembly was AUD350, with which I did not proceed.
Instead, I have now bought a new Denon DCD-700AE for AUD560. Have I done the right thing? The new machine is brand new technology, I suppose, but weighs five times less, very light and flimsy built. The sound is alright, quite like the old DCD-1520.

Any suggestion how to dispose of the old machine? I am still using it to read some odd discs that it plays, on my second sound system. It would be nice to find a cheaper way to fix it.

Stoozo.
 
I have the same problem with my DCD1520 but this is a process, the laser gets weaker and weaker. Now it's impossible to play CDR's and some bought CD's. I have tuned up the laser once but the machine is so old so I'll let it rest and buy a new one, especially since my daughter has damaged a button.

A new laser costs in England approx. 49 GBP so if you can fix it yourself it might be worth it. I think I have seen a place for half the price also but I'm not sure.

I Sweden I have read about people that have fixed it pretty easily.

Suitable keywords for google "Laser KSS151A DCD1520"
 
My experience with DENON CD and DVD players, when it comes to their ability to read low reflectivity disks, is very bad. The units come of assembly line marginal at best. It may be harsh to characterise all DENON players as being marginal – but this is what I have found with 3 DENON CD Players and 2 DVD Players I modified. The laser power is just enough to successfully read high reflectivity CD ROM’s. As soon as you try to play low reflectivity disks – there’s a problem! You can increase the laser diode power. You can’t loose anything – but gain a year (or much more!) of service.
The proper way of doing this requires circuit diagram (or knowledge of the whereabouts of RF test point), and a CRO. The idea is to adjust the eye-patter RF signal amplitude. I use one particular disk for this purposes that has very low reflectivity (original disk bought in a music shop). I posted a few threads on how to do this adjustment approx. a year ago… Try the search engine and “eye-pattern” keyword. You’ll hear a “warning” bul$#@ suggestions from many, saying that it is dangerous to do this – but all you will be doing is adjusting the RF amplitude for a nominal pp value (+- margin/tolerance)! It is a common misbelief that laser pickups come pre-adjusted; this is wrong; they have to be fine tuned for each CD Plaer / DVD Player if you want to obtain optimal results with all your digital media.

Boky
 
Administrator
Joined 2004
Paid Member
Hi Boky,
I disagree with you 100%. Sony head and chip set. I have seen that many are not aligned perfectly from the factory. The other issue is the linear motor. Those rail need to be cleaned and relubed from time to time. Those machines are real winners when set up correctly. The laser power however is aligned properly at the factory. If you are messing with that, you are hacking the unit.

If you have a problem with those, then you also don't like machines like the Tascam CD-401 and many others. It all comes down to the tech that sets it up. I really like those machines.

Now, I do have an issue with the nature of the complaint. Any CD off spec will be a problem. CDR's are especially bad. In the early days we had many Sony (and other) units that would strip the feed gear due to these discs. DJ's mostly. We set these machines to read standard CD's. If you feed the machine some off standard - oh well. I see market pressure has required a change in servo design to an auto - set type. Your loss. The tech aligned units are better with good source material.

Anyway, you can't knock Denon or other manufacturer when an older machine is acting up. Just the same as you can't blame the car company when your older car won't run on kerosene. At least parts are available! You can blame the local agent if their prices are too high and their work is poor.

-Chris
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.