"Mark Zacharias" wrote in message
...
"William Sommerwerck" wrote in message
...
Radio Shack had a head cleaner which is basically
a disk with a line of brush fibers across it.

I've owned optical-disk players for almost 30 years, and have never had
to
clean the optics of one for any reason.

The spinning disk tends to blow dust off the lens, so it's unlikely such
a
cleaner would ever be needed.



Disagree. DVD players seem less prone to benefit from cleaning, since they
are generally better sealed from the start, but audio cd players often
require (and benefit from) cleaning.

The spinning disc does nothing to keep dust from the lens. Even so-called
cleaning discs can't do the job, and they have brushes on them.

William may live in a clean place, but many of my customers do not. I've
been doing this for 30 years, and measured the level of many CD "eye"
patterns before and after cleaning, and have seen up to a 100%
improvement - increase in RF level, that is, after cleaning.

For example, often a player will show symptoms first on a CD-R disc before
having any issues playing a factory disc - and the same CD-R plays fine
after cleaning.

Mark Z.


Mostly agree. I think to some extent it depends on the type of crap that
we're looking for, and trying to clean. On a standard CD player, the disc
does not spin fast enough to have any 'dusting' effect on the lens, so on
players that come from a dusty environment, an improvement can often be
obtained by manually removing a collection of dust on the top of the lens. I
say 'improvement' because cleaning the lens does not, of course, address
dust that has also collected on the internal optics of the laser, ie the
critical angle mirror and possibly the pickup array where this is located
horizontally at the bottom of the head. Never-the-less, removal of the lens
dust will often restore near full spec performance. A less satisfactory
outcome is often the case where the lens is 'filmy' from tobacco smoke.
Whilst the lens is easily cleaned with IPA, the film on the internal optics
is likely to be as bad as the one on the lens, and although the laser may be
recovered enough to again play discs, the performance is often still badly
degraded, and from a service point of view, the only good outcome of this is
that you will have proved that the base cause of its original failure to
read discs, is indeed the laser, and not a circuitry problem.

DVD decks spin the disc much faster, and the rotating disc pulls a good
wodge of air round with it. In my long experience of servicing the things,
this makes it very rare for a DVD laser to appear on the bench, with a dusty
lens. The exception to this is if the player has stood unused for a long
period of time. Filmy lenses from smoke are much more common, and because of
the more critical nature of data recovery from a DVD, I have found that
cleaning seldom achieves a satisfactory result, presumably because
scattering of the laser light on the film covered internal optics, just
creates too many errors in the data stream.

As to the cleaning discs with a brush on them, my advice is to never ever -
that's NEVER - try to use one, particularly in a DVD player. On most CD
player lasers, the lens has a sort of 'wall' raised around its edge, and all
this serves to do, is deflect the brush bristles so that at best, a few of
them skate across the very middle of the lens. However, on a DVD deck, the
laser head is often rather more 'petite' and delicate than a CD laser, and
on more than one occasion, I have seen a laser destroyed by the bristles
getting caught in the lens suspension, ripping this off its mount.
Presumably, it's the high rotational speed that causes this.

Finally, I think that the OP has been incredibly lucky that his - how shall
we say ? less than conventional maybe ? - attempts to restore operation to
the unit, have not resulted in its total destruction ! :-)

Arfa