Replacing Sony KSS-240a laser in Arcam alpha 7 CD

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It will probably come as no surprise that I’d like to replace the kss-240a in my Alpha 7SE which can be unpredictable after a cold start. It may just be ‘sticky rails’ but as the laser mech. is so inexpensive I’ll change that at the same time.
It sounds ridiculous to ask but can anyone send me a copy of Kora’s pdf document - assuming Kora has no objection.
Thanks in anticipation.
Chander@woolcycle.com
 
Perhaps my new KSS-240a is faulty. I replaced the broken one in my Sony HCD-VF1 cd-player. It spins, focuses AND reads the cd. But the output is static. No music just static. I am confused, it is clearly sending bits to the player. Does this mean the KSS is DOA or does this mean that the DAC (or something else downstream) is broken?

Regards,

Bert
 
Yes, the original was dead in the water. Didn't read any cd's at all, just errors. Now it reads the cd's, it spins and it advances. In all aspects it behaves as if it is working. The display also shows the correct data. It's just that the output is pure static; which either means a DAC issue or a read problem on the KSS.

I do have a scope but not sure how to connect with this issue.
 
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You need to at least look at the RF and see it looks good and is of decent amplitude.

Pictures etc in this thread:
Sony CDP790 and KSS240 Restoration Project

Your Sony probably uses the same servo PCB under the pickup which to be fair are not the easiest to work on and access. The manual should detail exact test points but it is usually pretty easy to pick the signal up by having a look around.
 
Hmmm. I looked around and it is a damn pain to work on. But it indeed seems that the KSS is doing its job. The DAC is the issue but everything is connected as it should. Well, that is it for this cd-player then, not worth to invest hours in repairing it as this smells like a cascade somewhere. It's not my primary player anyway but would have been a nice gift to someone.

Thanks for the input!
 
Last time that i bought kss240 was 2010?
I bought this for a player witch original 240 had difficult reading.
The new one.... read nothing!
The seller give me another, again nothing.
Putting the original one (the old one)
, player repeat the previus difficult reading but still function!
A friend who was a Sony official technician gave to me a new one from Sony parts.
Player function like a new!
Same story with a Philips CDM12. 4.....
I think,now days,all these are for the bin.
 
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If we are saying that you think the laser and so on is OK then the only other part I've come across (it is relatively common as a failure) is a DRAM or memory chip that data is clocked into but the Alpha may not even use such a device as a separate part.

That was the problem here, post #102:
CD player with distortion. laser?

thimios... I know exactly what you mean regarding replacement pickups.
 
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