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Compact disk Sony CDP-395

This CD player has a little problem.
Sometimes when I am listening a record......I push the key to unload the disk and try to load the new one but the loading motor doesn't work.
I push the play key or another keys , like stop, next track, track nº 2, 3, and so on, and the display show the action but the cd disk is not loaded.
The only way to load it is to reset the equipment with the power key (turn off and on it)
After that, it works fine for about some minutes, or even an hour. You can unload and load the disk many times and it works perfectly.
But other times, when you unload the disk, the cd player reblocks as before.

I think is a problem of the microprocessor CXP-50112-097Q, who is the responsible of the display, and functions of the keys, load and unload the disk, and the motors and focus of the laser unit.
When the equipment is blocked I reset this microprocessor by the pin 32 (rst), and then it load the disk and begin to work.
I replaced this microprocessor by a new one, but I only can find and buy the CXP-50112-388Q.
It is different, is not 097Q, like the original, and It doesn't work. Whith the new one the display is totally off and none of the motors, load, unload, focus, can work. The equipment is fully dead.
If I connect the old microprocessor it works but with the problem mencionated before.

This microprocessor has a ROM of 12 Kb and I think here is the problem. The ROM of the new one is different and:
- I have to find the correct microprocessor CXP-50112-097Q
- Or I have to reprogram the new one CXP-50112-388Q

Another ideas?
Best regards



Re: Compact disk Sony CDP-395

Well, at the end the CD player was repaired.

I replaced the old belt of the loading motor for a new one, but the problem continued....
Then I checked the mechanical parts and cleaned the limit micro-switch of the laser head tray. It was a little bent and did not make good contact. I think this was the problem....sometimes it dont't have good contact when I eject the disk....

I resolded with tin all the elements of the BD BOARD, focus panel / sled / tracking / servo and cleaned the different connectors.

And finally the SONY CD player is working fine. The problem has disappeared

Thanks for your support and your ideas….

Re: Compact disk Sony CDP-395

First of all, I'm glad that you resolved the problem and all's good. Just to add to the mechanical side of things, for symptoms of intermittently not reading the toc (table of contents) or on reading the toc , no or certain tracks won't play, if after cleaning the laser lens with good quality (at least 99 % pure) isopropyl alcohol applied by a cotton swab, the problem persists, attention should drawn towards the spin motor. I have found that after the careful scant application of servisol super 10 contact lubricant to the upper and lower parts of the spin motor, normal operation is more often than not restored.

Re: Compact disk Sony CDP-395

Hi,

The takeaway is that these microprocessors have been programmed to expect certain responses within a certain amount of time. They have not been programmed for anything that is out of the norm. Hence, the lock-up and needing to be reset (rebooted).

-bob

Re: Compact disk Sony CDP-395

Thanks for your answers,

I have checked the mechanical part of this CD unit. It is over 27 years old.

I have been re-greasing the tray loading motor and I`ve checked the belt.
At the end I will replace the old belt for a new one.

I don’t think is a mechanical problem because when you push the un-loading key, the un-loading motor works perfectly, the tray cd go out but the microprocessor hungs up, is blocked. Then I push the loading key but the microprocessor don’t supply the loading motor.

The only way to load the CD is power off-on the unit or reseting the CPU by pin 32

Most of the times the CD player works fine. This is a problem that happens the random way.

I will tell you the results…..

Re: Compact disk SONY CDP-395

Sounds more like a mechanical problem to me; possibly dried grease that isn't allowing the tray to move freely or a bad belt that is used for loading (or both).

Re: Compact disk SONY CDP-395

I have checked the different pins of this microprocessor CXP-50112-097Q, especially pins 63 and 64, (switch load in and load out), and they works fine.

I have measure voltages on other pins and they are correctly.

Pins 67 y 68, (output motor load in y motor load out), only works fine when the cd player is not blocked.

Because of that I think is faulty this microprocessor.....

Re: Compact disk SONY CDP-395

I agree that it is / was much more likely to be a mechanical problem. As well as checking for hardened grease , check the tray loading motor drive belt and loading tray mode switches. The mode switches in many cd mech are notorious for causing all sorts of sometimes baffling symptoms. One of the golden rules of electronic servicing is, start with the basics and work from there.

Just to elaborate, I remember servicing an Aiwa 3 tray cd mech that refused to function at all after I replaced the tray motor belt with a slightly smaller one. To cut a long story short, the cpu hung up on detecting the raised current draw of the tray motor, caused by the smaller drive belt ! So although faults can sometimes seem to emanate from "the electronics" , quite often the cause is mechanical.