Sony CD head repairs !!!

[gmphadte]

Bought a Sony MHC-1700/FH656(Europe) Hi-fi audio system with dual DAC, at throw away price, CD was not working. Once it played for some time. Head assy is defective. On proper inspection found that the the lens is inclined due to support aging. Have new head assy KSS210B(t'was free). Wish to swap the lens assy to the system's KSS240A. Help please...

Gajanan Phadte
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Whose father's what goes

[mrfeedback]

You can try swapping lens assemblies but this requires alignment I think.
KSS-210 pickups are extremely common (in several brands apart from Sony) and economical, so you should be able to get a new one easily.
I have tried with success removing the pickup, removing the cover over the lens mech assy, holding the assy upside down and with a heatgun briefly heating the white hinges enough for them to sag, and then let fully cool.
This has helped but is tricky to do.

Eric.

[gmphadte]

thanks for the trick,
I am trying to rectify the KSS240A. Can I open the two torx screws and replace the lens assy. My worry is that, I find there is a difference in the actuator coils' number of turns and different magnets. Will AmpereTurns become a problem...

Gajanan
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[mrfeedback]

Lift the dust covers off and take a closer look, but I think the lens actuator assy's are the same.
There is a third screw for angle/height adjustment from memory.
You may be lucky that replacement lens/actuator assy lines up ok and works.
The ribbon cable on these pickups fail frequently too - the conductors may look ok but go intermittent at folds/bends near the ends.

Eric.

[gmphadte]

U'r right, nothing to lose........and lots to learn.

The repairs is quite a learning experience. Basically electronics but I especially like to work on mechanisms, alignments and things like that. You can see and feel the results. When I saw this challenge, couldn't ignore it. Here, I can buy a DVD player at lesser price than the KSS240A pick up.
Let's learn...

Before attempting the last resort i.e. swaping the lens assy, let's learn the intricacies.
I found that you can see a circle in the centre of the lens, may be the laser diode.
I put a support (below the weight) made from the audio cassette pad copper after halving it lengthwise. Things have changed. It doesn't work but it is now spinning for a short time. The support is too hard.
Inference: we are on the right track.
Will look for the third screw, attempt further, and will come again...

Gajanan
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If the geography is good, history will be bad.

[gmphadte]

The CD player is working fine with the copper support. It has not worked from local controls but when tried from remote, started working. After some playing everything is working(even local controls) except that the display shows an extra '1' in the forth place. Found that IC CXA14920 is getting quite hot. Suspect it will go with the wind, in the near future. Does anybody know what the IC is. Any schematics/help...

Enjoy...

Gajanan
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[Rusty777]

IC 205 - CXA 14920 is the GEQ 7 band electrical volume and it runs hot.

[gmphadte]

Rusty777wrote:
IC 205 - CXA 14920 is the GEQ 7 band electrical volume and it runs hot.

Thanks for the reply. Upto now, it is still alive but now I know

Gajanan Phadte

[prashbh]

I am working on a Sony FH-B711 music system.I do not have schematic . The lens (KSS240A)tries to read but the CD rotates and stops giving some chirp like sound.Lens is clean.Other fellow have mis tuned it.laser diode gives light.
Q:there are 3 presets on the lens.What are the functions of these. What effect will be if i rotate them?
Prashbh.

[gmphadte]

Put the player upside down and try if it works,
and report back the result

Gajanan Phadte