"dave" nospam writes:

Hey Afra,

You may have me there. I've only repaired two CD changers. One Yamaha had
a hairline crack on the stepper motor gear that caused it to skip
intermittently. One Denon did have bad tray sensor switches. It had a hard
time loading disks because of it.

But my point was more to do with the way some things are blanketly
diagnosed. I have much more tape machine background. I don't know how many
times a lay person would hand me a bad tape machine and tell me it probably
just needs the heads cleaned. I'd be like "sure I'll clean the heads for
you. How about I fix it after that?"

DaveL


I remember there were some Sony models (I think) where the speed of the motor
that rotated the corousel would drift with time and then the player wouldn't
even recognize that there was a disc in any position. A resistor/pot
fixed that.

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"Arfa Daily" wrote in message
...

"dave" nospam wrote in message
. ..
Sam is correct. Let's see, the player does not detect CDs so check the
lense for dust? It could be a bad laser? Not even close! CD changers
generally have sensors to tell them which slots have disks in them. I'd
check those sensors first. Also the change/loading mechanism could have
sensor switch problems.

DaveL


Sam, or indeed you, *may* be correct - it depends on what exactly the OP
means by the player " failing to detect a disc ". In my experience, this
is normal-speak for the player not extracting a TOC from a disc, maybe
after a spin-up, maybe not even getting that far. It is very very rare for
a player that has separate disc detection, to fail to sense that a disc is
on the carousel at any particular position. Many players do not have
separate disc detection sensors, relying on the laser to find something
when it initiates a focus search. This particular player does use separate
optical sensors for both disc and carousel position detection. However, I
can't remember ever having a problem with one failing to sense discs on
the carousel.

Having repaired many of these, I would fire the same statement of " not
even close ", back at you. In my experience, the most common playing
problem on these is due to a defective ( or just plain dusty ) KSS240A,
and the liklihood of any sensors being at fault is slim at best. I have
had the laser flexiprint go bad, and that usually results in failure of
the focus motor to operate, as the tracks that normally break are the ones
that connect to there. This is easily spotted by watching to see if the
lens goes up and down ( having first fooled the sensor into thinking that
there is a disc in place, of course ...) Very often, a poke of the
flexiprint at that point in time, will cause the tracks to momentarily
remake, and the lens will move.

And to Sam, yes, I would say that the situation is that bad now. The
quality of the 'standard' Sony KSS series lasers, fitted to many
manufacturer's products, seems to have gone down and down over the years,
and I change many of them - often in kit that's still within the warranty
period, which is often about the only time that it's financially viable to
do it. The latest Sony offering in the laser stakes, is not even
replaceable. The flexiprint is solder-attached at both ends, so the whole
assembly has to be replaced, complete with the servo / amp pcb, which also
is not really servicable, as the IC is one of those calculator style "
ball of snot " jobs, that has no visible pins for measuring on.

Arfa