Onkyo cd player problem.

[marchel]

Dear all,

My old Onkyo cd player is having a problem. It does not read the disc anymore.

I opened it up to see, When I load the disc, the disc don't turn and does not read TOC, But there is light coming from the laser and the laser moves up and down, when loaded with out the disc.

I have adjusted the pot near the laser, But the problem was not solved.
The cd head reads sony kss213. Could this be the culprit?

Thank you.

[Mooly]

The pot on the laser should never be altered... it's factory preset and sets the laser current. If you have just turned it up you might have damaged the laser diode anyway. The serial number of KSS type pickups incorporates this value as the last three digits so 4521225457 would be 45.7ma.
Before condemming the pickup, make sure the sled is in the correct position. If you wind it out manually and then power off and on it should move back to the correct position near the turntable. Also is the turntable motor OK... they do fail if it's a cheap DC type. If in doubt disconnect it and see if it runs with a 1.5 battery. You can use a 9 volt battery to "burn" and contamination of the commutator, which is bodge job but might help prove if it's the cause of the problem. The disc won't spin until the laser has focused... it's easier to focus on a stationary object than a moving one.

New pickups
http://cpc.farnell.com/jsp/search/br...questid=143048

[marchel]

HI, Thank you very much,

Could it be possible that the laser unit is defective even if it still emits light?

Btw , I'll check the motor too.

Thank you.

[Mooly]

Yes, the laser can become little more thn a side emmiting LED when it fails, it still illuminates but there is no lasing action... having said that though, laser failure as such, isn't as common as you might think.
Usually problems build up over time, it becomes increasingly temperamental playing discs etc.

If you have a circuit there is a point called FOK which is focus OK. When the lens finds focus on the disc, the logic level of this line should change state, that then tells the disc motor servo to spin the disc to approximately correct speed, at which point the data stream is phase locked to an internal crystal oscillator, which then takes over precise motor speed control.
I take it the lens is clean ?

Without a 'scope and service info, and providing any adjustments in the player haven't been altered it's worth trying a new pickup... but there are no guarantees... without actually having the player to look at it's all guesswork.

Some of the adjustments (EF balance and offsets) are very critical and must e adjusted correctly if they have been altered.

[marchel]

Hi,

I opened another cd player to compare the intensity of the light coming from the laser, And this onkyo cd player emits very weak light, So now I can conclude that the laser is really the culprit.

About five years ago, I tweaked the pot , Because the cd player skippped alot when reading near the outer edge of the disc, It has solved the problem, And then The skipping came back a year ago , I tweaked it again, And again the problem was solved, Until just recently , When the player does not read the disc anymore.

Once again thanks for the help, I'm gonna go buy a laser head for this cd player.

[Mooly]

Worth trying for sure. Always be careful when looking at the laser light as most of it is in the infra red... it may look dull and dim... but it isn't. View from at least 18 inches and obliquely.

Make sure you remove any shorting link after the pickup is connected.

[marchel]

Hi ,

I'd like to update this thread.

A replacement kss 213c arrived yesterday, I mounted it today, And I'm happy to report that the cd player is now working like new.

I've learned through the internet that, There is a solder blob on the board of the kss 213c that needs to be un-soldered to disconnect 2 solder pads, To make the laser head work.

Thank you very much.

[Mooly]

That's good... thanks for letting us know.