CD63KI problems - please help

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Hi
I have a problem with a modified CD63KI. It seems to read discs ok but halfway through a track it will stop producing sound (other than popping or cracking sounds). The cd still spins and displays timer progress.

Then after about 10 minutes sound would return, then it would skip or play for faster for a few minutes then produce no sound and this will go on until the end of the cd.

Any advice on where to start will be appreciated.
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Yes, wait until the player is in the faulty state and then drip the freezer. It's possible to dispense the freezer literally one drop at a time with practice. There's no specific order but perhaps start with the large signal processing and DAC chips.
 
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Do you mean that the above buttons do what they should (for ex jumping to the nexr track) and then the player commences to play again OK or that the action of pressure on the buttons causes the player to work ?

The bottom line with this is that you need to put a scope on it and start by looking at the RF and seeing what is going on. You say its been modified too so there are a lot of possibilities for problems.
 
It appears that the buttons do both:
1) they do what they should ie fwd, back, pause, stop etc.

but if depressed while the machine is in 'fault mode' ie no sound;
then any of the buttons marked << or >> or pressing pause twice will get the specific track to fwd or backtrack or pause and then play as normal.
I hope that makes sense.
 
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I can't think of anything specific. One possiblility could be that the "tracking" is marginal and the player is right on the edge as it were. If the quality/amplitude of the RF is low then the same thing can occur. When you do something drastic like a track jump then it manages to lock for a while.

It could even be something like the laser pickup but without detailed tests and checks its all guesswork.
 
I have a Velleman 5mhz battery powered, hand held 'scope will charge it up and see if it is suitable to start with. I have taken the player apart and inspected pcb for and dry solder joints, also checked connectivity between pins on SM5872BS chip and pcb/components no problems there.
 
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All discs give the same pattern irrespective of the content. Just use a good quality normal music CD and never a CD-R or CD-RW. Reflectivity can vary a little so try a couple to make sure that you haven't just picked a poor one (which would give low amplitude of the RF). Most discs give around the same level.
 
suggestions

Thanks for the suggestions so far. I am waiting for delivery of some DOW- Molykote grease for the clean up and re-lubing of the rails and gears on the cd63. I was lucky to get access to a 'scope which I will have this evening.
Going to be an interesting weekend.:magnify:

Will keep you updated.
 
unfortunately..

The oscilloscope had to be returned to the workplace of origin after my weekend of exploration. I only managed to record wave patterns from R501, R502 and R503 during normal play. Could not measure patterns to compare during the times of faulty (audio/no audio) output as I could not get the scope to 'trigger' at these times.
 
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You would have to leave it playing with the scope displaying the RF.

When you say it would not trigger at the faulty times, then if it was correctly displaying the RF before and that changed when faulty then that needs looking at. That could well be a pickup or front end problem.

The RF should be steady and unchanging from disc to start to finish. The only time it looks different is in the interchannel space between tracks.
 
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