KSS272A working or not

[tdi]

I am looking for any KSS272A.
Sony no longer makes them & no one has them new anymore.
If the old one can be repaired with a new bulb. ???

[kevinkr]

Bulb? The semi-conductor laser diode and photo diode assembly isn't serviceable...

[tdi]

Originally posted by kevinkr
Bulb? The semi-conductor laser diode and photo diode assembly isn't serviceable...

Are you 100% sure of this?
We are at DIY.

I still would like to take one apart to see for myself why.

[kevinkr]

Originally posted by tdi



Are you 100% sure of this?
We are at DIY.

I still would like to take one apart to see for myself why.

Your reality and mine might be different so I can't say for sure, however I know of no instance where this has been done successfully in a hobbyist environment. You'll need a lot of patience, the right tools, a powerful stereo microscope, some way to remove the old die and attach the new one.. I definitely could not do it, but I'll not put that limitation on you.

The ones I've experimented with were never meant to come apart. (Philips and old Sonys)

[Mooly]

Hi Kevin,
Have to agree with you but,
Stripdown/Clean of CDM12.4

I never did try the final step, removing and replacing the diode array. The Sony probably has a diffraction grating adjustment ( nightmare ) and having to position a laser and adjust this, no way. The Philips CDM 12 pickup has no such adjustment. Would love to try it sometime.

tdi --- Does the KSS272 have a separate photo diode array? It's just as likely to be a problem here as with the emmision of the laser diode. Have you confirmed the laser to be kaput. Current check ? Where would you source a replacement diode ?

[tdi]

Originally posted by Mooly

tdi --- Does the KSS272 have a separate photo diode array? It's just as likely to be a problem here as with the emmision of the laser diode. Have you confirmed the laser to be kaput. Current check ? Where would you source a replacement diode ?

As far as I have gotten is:

I have a X707ES that is not tracking anymore.
This stuff my be way over my head personally but.
If there is any way to keep these old great players alive.
Many would be very happy.

I do not want to start with taking mine apart.
That is why I am looking for any KSS272A's dead or alive.

I know that there is only so far I will get with it.
Then maybe someone else can get farther.
Maybe Sony will start making them again.
This may all be wishfull thinking.

I do have a X33ES with a KSS270A that is working.
Some say it might work in a X707ES.
I will try that at some point but it is still used and will burn out.

ed

[Mooly]

I am not familiar with the KSS272 but many of the Sony KSS types have the current consumption of the laser diode as part of the serial number on the pickup. So xxxxxxx527 would be 52.7ma.
That value is unique to that pickup and it's usually possible to measure by reading the volt drop over a 10 ohm or similar resistor on the main PCB. You would need a circuit. That value tells a lot, if it's increased by more than say 10% that means the laser is failing.
Have you cleaned the lens properly ?

[tdi]

Originally posted by Mooly

Have you cleaned the lens properly ?

what is the proper way to clean the lens?

[kf_tam]

Repair laser head required a lot of LUCK!
You first make sure whether the laser is dead or not.
To replace the laser and still maintain the optical alignment without factory facility is nothing more than blind guess. I heard some guys in the Mainland China has good luck on replacing the laser on KSS-16X. But when I try transplanting the laser from a KSS-220 to a KSS-16X it didn't work.

If it is the lens couldn't focus due to gravity deformation of support system (a plastic parallelogram style structure in most Sony), then it is possible to sweep just the lens structure because many Sony laser use nearly identical lens structure, with a few exception. Examine carefully to find a transplant target.

But it is still trial and error to find one work (i.e. maintain to optical alignment), so prepare some more. I once tried to sweep lens of the KSS-151 with focusing problem from four lenses from KSS-330/KSS-220/KSS-162. With some desoldering / unscewing, the KSS162 lens worked while the KSS-330 didn't. Didn't try the KSS-220 lens.
After that you still need adjust the various variable resistant pots in the CD player with the help of an oscilloscope and service manual.

[Mooly]

Lens cleaning ! I always use a proper lens cleaning solution ( Sony part no ) so what are the alternatives.
I have never tried it but I bet camera lens fluid would be OK. Officially you should never use isopropol alcohol, Sony did a U turn on this 20 years ago. It can damage the coating on the lens. Never use glass cleaner either.
Failing all that I would use plain water, possibly with the tiniest drop of detergent in.
You need a good quality cotton bud with the end teased out so it's not to hard. Dampen the bud slightly and gently clean the lens. You have to be careful--common sense. Use a torch to see if it's really clean, no marks left. If there are get a dry bud, teased out a bit, and gently polish the lens.