On Thu, 10 Mar 2011 02:09:10 +0000, Arfa Daily wrote:

"Meat Plow" wrote in message
news
On Wed, 09 Mar 2011 01:36:57 +0000, Arfa Daily wrote:

"Meat Plow" wrote in message
news On Tue, 08 Mar 2011 10:36:44 -0800, GARY wrote:

No error-code.

After the 3 discs are cycled over the lens, the display says "No
Disc".

You've got problems in the logic portion. If it were a laser problem
the disc would rotate and the sled would slide the laser block in and
out looking for a disc ID.

Often not the case, Meat. Many players will not start to spin the disc
up or move the laser down its slides, unless focus lock is obtained,
The movement of about an inch is often an attempt to move the disc to
a different spot to retry the initial focusing operation, in case the
original spot on the disc was dirty or damaged. This small movement of
the disc may be carried out just the once, or several times before it
gives up and declares there to be no disc ...

Just as a matter of interest, why has the OP started a new thread,
instead of continuing with his original, also called "Compact disc
doesn't spin" started two days ago ?

Arfa

I must be thinking of a DVD. Looking at this portable player with a
window to see the disk as soon as the lid is closed the disc rotates
and then the sled moves in and out. Been too long since I've worked on
a CD player to remember if they do the same I guess.



No, no. You're quite right. Some players do just go ahead and spin the
disc up regardless, but by far the most common scheme is to first home
the laser, which is usually just a little shuffle if it's already home,
then to obtain focus, and when that is achieved, spin up the disc and
get the tracking servo locked before finally starting to read data to
extract the timing for the spindle servo. Once all of that is
acomplished, the TOC is read in.

Arfa

Got it. I always assumed the laser needed a spin to focus. Working on
those things back in the 80's when they first hit the market and the vast
majority were warranty items it was more time effective to just shotgun
the entire mechanism than to spend more than 10 minutes troubleshooting.
I made the most money per piece with a horribly low minimum wage salary.
And the facility was well stocked with factory replacements. So it was
check a mental flow chart, if it was a tweak or a mechanical problem that
could be buttoned up in 15 minutes then it actually got some repair.
Otherwise it was pulled and replaced. So even though countless boxed units
from several retail chains made it to my work area, I didn't have the
time to get real intimate with the workings. By the 90's I switch from
consumer to pro audio repair for a friend who did Yamaha warranty. Better
pay and I got to spend more time with power amps, synths, etc...



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