Puzzle with warmed up player....

[Lyra]

I have a problem....

One of my players sometime have a slight problem starting reading the first track of some of my CD-R's. (not all)

-if it first manage to start it works great....

-if i push play, and "forget" it, it might starting to play over an hour later....

-if I jump to track #2+ it allways start immediately, and I can fast-rewind back to beginning of track #1, and it plays it without problems....

-it have no problems with this when the player is cold....

-the problem allways occur with the first track....

-Sometime it won't read the TOC (of the worst CD-R's) when warmed up, but OK when cold....

What is this ?
........or could it be.....

....bad laser ?
....bad allignment/ adjustment ?
....bad movement of the laser ?

Lyra

[Netlist]

Cleaning the laser is definitely the first thing to do.
What Brand/Type is it?

/Hugo

[Lyra]

Originally posted by Netlist
Cleaning the laser is definitely the first thing to do.
What Brand/Type is it?

/Hugo

It si a Denon DCD-2560 containing a KSS151 Sony Laser.

I have cleaned the lens with good isopropanol (the one without colour...). It didn't help regarding this problem, but I think the player is more tolerant with original-CD's after that.

BTW: sometimes the "bad" CD works even when the player is warm.....and then if i push stop, and play again it might not be able to start track #1 again.....
...this make me think that it might have something to do with the movement of the laser.......

...and if it was a problem regarding the speed used when burning the CD, the problem should be bigger at the end of CD as the speed here often is higher when burning....and reading....!?

Lyra

[Netlist]

You should only clean lenses with distilled water.
I have no experience with the DCD-2560 so I can't give you specific info.
It could be the laser, some worn out caps, a bad chip, no idea.
I would go for the laser, unfortunately it’s a rather expensive one just to try but you would have a spare one for future use.
You'll need the Denon guru's to solve this issue.

Did you try with CD's burned by someone else?

/Hugo

[johnnyx]

Warm - up related faults can be diagnosed with a can of freezer spray. When the unit is warm, spray chips in turn waiting between each one, until you spray the one which makes it work.
I worked for a company which repaired CD jukeboxes for a while, and the best way of diagnosing a faulty laser is with a laser power meter. I suspect that it's a faulty decoder chip though. We used isopropyl alcohol to clean the lenses, applied with a cotton bud. Be careful! One installation engineer scrubbed the lens with a toothbrush, we couldn't repair the mangled wreck he created! It wouldn't do any harm to freeze the laser, if you want to eliminate that for certain.
Hope this helps.

[charlesjudd]

I have a Primare D30.2 CD player (Dual Burr Brown DACs and Sony transport). I experienced intermittent CD playback with some burnt audio CD's. Some CD's would play fine when they were first inserted, but then they would become full of static or skip near the middle of the CD. Some CD's would take a long time to load or would intermittently not load or play at all.

Turns out the problem was the speed with which the CDs had been copied. Any CD that is copied at a higher rate than 1x exhibits the problems I mentioned above.

It is a bit painful having to copy CDs at 1x but it does seem to improve their reliability for audio.

Good Luck

[Lyra]

Originally posted by charlesjudd
I......., but then they would become full of static or skip near the middle of the CD. Some CD's would take a long time to load or would intermittently not load or play at all.

Yes this is logically......as the speed both in read, and write operations increases the longer out on the CD-medium you get.

My fault on the other hand is only "active" at the start of the CD (where the speed is at it's minimum), and when it just manage to start it newer !!! get any problems later on.....that is if there isn't any deep scratches on the CD-surface. If this is the case, it jumps a little back and fourth and the jumps over the fault and plays the rest.
I can repeatedly push play/stop a couple of times and then it usually starts playing, but with only "play" it can go forever before it starts.

Lyra

[Cobra2]

...at the start of the CD (where the speed is at it's minimum)

The Cd starts from "center", at the highest speed....

Arne K

[Lyra]

Originally posted by Cobra2

The Cd starts from "center", at the highest speed....

Arne K

Yes it starts from center, but not with highest speed....don't think so...see below....this is a CD-ROM but think the same physical law's applies to an "ordinary" CD-player.

Lyra

[Cobra2]

Hi!
You are mixing reading speed with rotational speed...

Arne K