My discman SONY D 250 bought in the 80's has some trouble : CD is turning, optical block is moving , lense is gowing up and down but after few seconds CD stops. I think the system cannot focus because the laser beam is too weak.
Tjhe optical block is a KSS-165A.
Does somebody know where I can buy that item ?
If it is obsolete, is it possible to change only the laser diode itself ?
Tjhe optical block is a KSS-165A.
Does somebody know where I can buy that item ?
If it is obsolete, is it possible to change only the laser diode itself ?
From what I have seen and asuming that the part number is 8-848-096-11 looking on encompass parts there is a substitute/alternative part of 8-848-162-11 Kss-221a.
found one here OPTICAL PICKUP KSS221A/165A [KSS221A/165A] - US$20.00 : Alltronic, One Stop Online Shopping
found one here OPTICAL PICKUP KSS221A/165A [KSS221A/165A] - US$20.00 : Alltronic, One Stop Online Shopping
The last three digits of the pickup serial number show the correct (original) current. Is it 419 ? That would be 41.9 milliamps and is checked by measuring the volt drop across a resistor in the laser power circuit on the main PCB and calculating the current. If it is higher than stated by 10% or more then the laser has deteriorated.
That reading is spot on. The visible light from these lasers is very dim, most of the emission is in the near infra red. That's why you can't "see" it. If you could then it would be very bright indeed. One reason you shouldn't look to closely at close range.
That doesn't help your problem though... all it does is show the actual laser diode is OK. If it had been duff it would have been case closed
So as it stands there could still be problems with the pickup as a whole.
Next step (as you mention it does spin a disc at the start) would be to look at the RF signal for amplitude and quality.
(From an economics point of view repairing this doesn't really make sense... you can buy a new player for a fraction of the cost of a new pickup... and it will be an all round better performer too)
Its in my last post Its because the wavelength of the laser light is 780nm on early CD players and around 650nm on ordinary DVD players. Look at this chart which shows the response of the eye. The CD player at 780nm is off scale and should really be invisible to the eye... and it almost is. You just see a tiny dull red pinprick glow.
Its because the wavelength of the laser light is 780nm on early CD players and around 650nm on ordinary DVD players. Look at this chart which shows the response of the eye. The CD player at 780nm is off scale and should really be invisible to the eye... and it almost is. You just see a tiny dull red pinprick glow.Attachments
You can't judge a laser by current alone. You have to judge by optical power output AND current drain. If it takes 20% more current to get to 0.1mW(0.15mW for older, and 0.24mW for REALLY older lasers) measured optical power, then the laser diode is dying.
I think I may have a KSS-165 or 221 in my old inventory, maybe more than one, but I'd have to dig around. PM me to remind me to look when I'm at my shop. Although I can't imagine why you'd want to invest any money/effort on this particular unit.
I think I may have a KSS-165 or 221 in my old inventory, maybe more than one, but I'd have to dig around. PM me to remind me to look when I'm at my shop. Although I can't imagine why you'd want to invest any money/effort on this particular unit.
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