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
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 said: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
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
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
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.
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.
CD Burn speed
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
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
Re: CD Burn speed
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
charlesjudd said:
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
CD player should speed the highest at inside of the CD and slow down on its way out.
Some physics could show us that using radius of the CD, you can calculate that the amount of material tavelling by at the outside of the CD is faster than that in the inside for the same speed. Therefore, if you wanted a constant read speed, you could spin the disk fast at the inside and decrease the speed on the way out, which is how the CD players I've seen have worked.
Some physics could show us that using radius of the CD, you can calculate that the amount of material tavelling by at the outside of the CD is faster than that in the inside for the same speed. Therefore, if you wanted a constant read speed, you could spin the disk fast at the inside and decrease the speed on the way out, which is how the CD players I've seen have worked.
Cobra2 said:
OK. I know that 1x (or 150kb/s) is the read-speed of a CDP.
This means that if the player can't get up the RPM enough this typically would cause problems at the beginning of the medium !?
Can think of several things that could cause RPM-slowdown: not perfectly-round media, old mecanics/motor, bad regulation of voltage to the motor, old motors need typically more current than new ones...etc.
....maybe this could bee the cause of my problems ???
especially concidering that repeatedly pushes on play/stop eventually starts the playback....think I should look for some noisy supplys.....maybe caused by some old cap's.....
Thanks !!!
Lyra
Puzzle
Hi Lyra,
Maybe your laser has a problem to get to the start position. This may be due to dirty gide rails and or dirty toothwheels. Also check that the flexicable is not obstructing movement.
Or if the turnatble has troubles in reaching speed may a worn motor.
Did you read my post for the PCB layout for the KWAK-CLOCK? You will find a lot of interesting information in the links!
Hi Lyra,
Maybe your laser has a problem to get to the start position. This may be due to dirty gide rails and or dirty toothwheels. Also check that the flexicable is not obstructing movement.
Or if the turnatble has troubles in reaching speed may a worn motor.
Did you read my post for the PCB layout for the KWAK-CLOCK? You will find a lot of interesting information in the links!
Re: Puzzle
I've been thinking about this, but is the start-posision different on a CDR versus an ordinary CD ?
(my problem never occurs with original pressed CD's)
Yes ! found some answers there. Thanks !
I will try to post a picture of my clock-layout in the respective tread....
Lyra
Elso Kwak said:
I've been thinking about this, but is the start-posision different on a CDR versus an ordinary CD ?
(my problem never occurs with original pressed CD's)
..........Did you read my post for the PCB layout for the KWAK-CLOCK? You will find a lot of interesting information in the links!
Yes ! found some answers there. Thanks !
I will try to post a picture of my clock-layout in the respective tread....
Lyra
This sounds like a problem that used to plague the old Philips 930 player. The start position of the TOC can vary a bit and the inner end stop for the pickup was set a hair too far out. Some discs would play fine, others would take a lot of attempts. The fix was to adjust the stop a tiny bit so the pickup could go further in.
That could be worth looking at, at least.
Colin
That could be worth looking at, at least.
Colin
Now I have tried another thing.....I burned a CD at 52X !!! and it plays 100% well in my Marantz CD40, and in my car....
....AND it plays right now in my Denon DCD-2560. I put in the CD before the player get warmed up, it checked the CD OK, and just plays it.
I have played allmost the whole CD, and then <fast-rewind> it to the start to make sure it is warmed up long before it reaches the end of the CD.
I am pretty sure thow that when it reaches the end, and is going to start over (repeat all activated) it will NOT play this CD anymore.
I tried this CD yesterday, and then the Denon wouldn't even read the TOC........
I think this tells me that the laser is capaple of reading theese difficult CD's, but there is something in the phase of checking the CD that fails when the player is warm.
If it was the laser that was faulty, it would crash the playback long before it finished the CD
Lyra
....AND it plays right now in my Denon DCD-2560. I put in the CD before the player get warmed up, it checked the CD OK, and just plays it.
I have played allmost the whole CD, and then <fast-rewind> it to the start to make sure it is warmed up long before it reaches the end of the CD.
I am pretty sure thow that when it reaches the end, and is going to start over (repeat all activated) it will NOT play this CD anymore.
I tried this CD yesterday, and then the Denon wouldn't even read the TOC........
I think this tells me that the laser is capaple of reading theese difficult CD's, but there is something in the phase of checking the CD that fails when the player is warm.
If it was the laser that was faulty, it would crash the playback long before it finished the CD
Lyra
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