Hell Forum......I have just got a cdp507esd player in for a checkup. The owner complains of distortion/scratchiness that follows the music. Faster music...faster scratchiness.....and vice-versa.
The player is in very good condition and does work. What would be the first thing to check?
Any info is good info. Thanks.
The player is in very good condition and does work. What would be the first thing to check?
Any info is good info. Thanks.
I have the unit in hand. I played a cd while listening through earphones. It is a constant scratchiness........seems like same speed as the cd is rotating. Music is clear......just this 'scratchy overlay'.
Is this fixable? (Within reasonable cost of course.......🙂)
Is this fixable? (Within reasonable cost of course.......🙂)
This could very likely be a very simple servo adjustment issue, but you'll need an oscilloscope, minimum, to get it right.
Ok.......of course I (still) don't have a scope. I may be able to borrow one though......how is the procedure done? Will this be stated in the SM?
Thanks.
Thanks.
The procedure will be stated in the manual but probably outlines using a frequency/gain analyser which no one has.
This thread may help you understand what are basic adjustments... and essentially most players are very similar,
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
This thread may help you understand what are basic adjustments... and essentially most players are very similar,
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
Mooly...thanks for the information! Thanks for pointing me towards that excellent thread.
(Maybe it is time to get a scope!)
(Maybe it is time to get a scope!)
Hello again Forum....I have been fiddling with player a bit........I still have the problem. Since the scratchiness is equal in both channels...could it be a power supply problem?
The scratchiness has the 'same' speed as the spinning cd......is this a clue?
I disconnected all the connectors and reconnected them.......just in case it was just a connection problem.
Anyway any ideas would be awsome.....
Thanks.
The scratchiness has the 'same' speed as the spinning cd......is this a clue?
I disconnected all the connectors and reconnected them.......just in case it was just a connection problem.
Anyway any ideas would be awsome.....
Thanks.
Difficult diagnosing noises at a distance.
If you take a good CD player and very very carefully use your finger to "slow" the playing CD you can create a very specific type of distortion/noise on the audio output. Of course if you "slow" the disc to much then the servo drops out and the player throws a wobbler.
Is it that kind of noise ? If it is then it could be a pickup problem and a marginal signal.
If you take a good CD player and very very carefully use your finger to "slow" the playing CD you can create a very specific type of distortion/noise on the audio output. Of course if you "slow" the disc to much then the servo drops out and the player throws a wobbler.
Is it that kind of noise ? If it is then it could be a pickup problem and a marginal signal.
It is possible that the 16k error correction ram chip is going bad. Rare, but happens, and creates this symptom. It'll be a CK5816M or something like that.
Ok...great ideas guys....I will investigate it.
The player is ultra-sensitive to any touch too. I used a plastic toothbrush to poke around inside the unit........even very, very light taps causes the music to fall out. Even very light taps on the plastic chassis causes this. It hardly matters where I tap.......main board...loader.....chassis.....then there is a fall out.
The player is ultra-sensitive to any touch too. I used a plastic toothbrush to poke around inside the unit........even very, very light taps causes the music to fall out. Even very light taps on the plastic chassis causes this. It hardly matters where I tap.......main board...loader.....chassis.....then there is a fall out.
When I pause the music.........there is no scratchiness(disc still spinning).
I have looked in the SM to find the RAM IC......is it IC303?
There is also a 'defect control' IC....IC203..............
I have looked in the SM to find the RAM IC......is it IC303?
There is also a 'defect control' IC....IC203..............
The tapping thing makes me think there is something else up. Absolutely abnormal behaviour. Rather than tapping, if you press down on the main board in various spots & it still causes fault, then I'd carefully examine the whole area for cold solder joints. If not, then either your servo adjustments are still incorrect, or the laser's focus actuator suspension is getting weak, which would be confirmed if the senstivity reduces if you tilt the player up past 45 degrees toward the right side(may need to support the mech suspension somehow to keep disc or disc clamper from scraping).
If I tilt the unit.........the sound definitely falls out. .............
My unit does not have IC303 or IC302...............
My unit does not have IC303 or IC302...............
Why not record the sound direct from the line out (use Audacity ?) and post the file on dropbox (or make it a small MP3 and zip it and attach to the forum. It need only be 20 seconds or so)
Any player should stand being tilted. We don't know if this is a physical issue or just a marginal signal from the pickup where the slightest disturbance upsets it.
(You really need at least the basics of an oscilloscope to work on and diagnose player issues but there is still hope 🙂)
Any player should stand being tilted. We don't know if this is a physical issue or just a marginal signal from the pickup where the slightest disturbance upsets it.
(You really need at least the basics of an oscilloscope to work on and diagnose player issues but there is still hope 🙂)
Mooly.......gosh, darn, gee-whiz and popcorn! I NEED A 'SCOPE!! I have been putting a scope purchase off for to long. X-mas is a'comin'...note to self....maybe give the wife a headsup!
Anyway........the music itself is clear......just the *******' fetfetfetfetfetfetfetfet-sound. I will try and record it.
It would be a shame if it cant be fixed.....these are nice units with high quality components inside.
Could it be a 'loose' laser?
I have worked on tons of stuff....just never cd players. I post a lot on the AK forum......
Anyway........the music itself is clear......just the *******' fetfetfetfetfetfetfetfet-sound. I will try and record it.
It would be a shame if it cant be fixed.....these are nice units with high quality components inside.
Could it be a 'loose' laser?
I have worked on tons of stuff....just never cd players. I post a lot on the AK forum......
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It won't be a "loose laser", as in a loose pickup assembly but the lens suspension components can alter (deteriorate) over time as Stephen pointed out.
A scope check takes all the guesswork out of it.
A scope check takes all the guesswork out of it.
No scope.......YET! :-/
When I tilt the unit to 90 degrees...the disc spins, but no output or scratchiness. ONLY when there is output there is scatchiness.
Some kind of laser-tracking-alignment-problem...............me thinks. I dont think there is anything wrong with the main board...all solder looks good...checked with loop.
The scratchiness is equal in both channels...........this makes me think that all the IC's, caps an'all are ok.......somekind of mechanical noise sneaking in somewhere.....
When I tilt the unit to 90 degrees...the disc spins, but no output or scratchiness. ONLY when there is output there is scatchiness.
Some kind of laser-tracking-alignment-problem...............me thinks. I dont think there is anything wrong with the main board...all solder looks good...checked with loop.
The scratchiness is equal in both channels...........this makes me think that all the IC's, caps an'all are ok.......somekind of mechanical noise sneaking in somewhere.....
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