Conference cookie::notes$archive:cd_v1

    Well, I'm sure this isn't what you want to hear, either, but this
    is what I do.  I happen to have 3 CD players readily available to
    me: my shelf model on the stereo system, my portable, and my wife's
    quite nice quality boom box.  If (after cleaning) the CD misbehaves
    in more than one of them, I blame the CD.  If it only misbehaves
    in one of them, I blame the player.  (This is kind of like the voting
    method used in many fault tolerant computers, I guess.)
    
    So far, I have had one player problem (which is why I replaced my
    portable) and about 8 bad CDs out of around 300.  Unless you start
    having problems with multiple CDs at the same time, the odds seem
    to be that it's the disc.  If you have friends with CD players,
    have them try the discs you have trouble with.  It's certainly cheaper
    than buying more players, and it's pretty difficult for a friend
    to damage your CD if they exercise reasonable care.  While CDs are
    more difficult to diagnose than LPs, their better wear characteristics
    make it reasonable to ask your friends to try them.
    
    B
    

    I have one of the Crown Portables (Paid $68.00) which I use at work.
    On this machine, I hear the pulse sound towards the end of program
    on perhaps a quarter of my discs.  These however will sound fine
    at home.  Considering what I paid for the player and the volume level
    that is tolerated by my co-workers, the problem is not too distressing.

    Also, I would recommend removing, re-seating, and re-inserting the
    disc a couple of times too.  I have had a couple of discs which,
    if not placed *exactly* in the center of the load tray, would not
    track (much to my chagrin).  These same discs *would* track if I
    just removed them from the player and tried again.  Any other disc
    in my collection was just fine, and since the disc would play on
    subsequent attempts I cannot (really) blame the player.
    
    
    FWIW,
    David.

    I think what happens is that there's a certain tolerance in the degree
    to which individual discs conform to specification.  Some players,
    newer ones in particular, tend to have larger tolerances than others. 
    I too have 3 cd players available.  I have about 4 or 5 discs which
    mistrack on one player, but which play ok on the other two.  At some
    point, I'm going to upgrade the one that mistracks, but it hasn't
    gotten that serious yet.
    
    -pd

Some of the static noises get created when the laser servo
starts drawing lots of power.  Towards the end of the disk
on longer disks, sometimes the track that the laser moves
in gets sticky.  That makes it hard for the motor to put the
laser in exactly the right position.  So it keeps adjusting.

Short of taking the thing apart and lubricating it, I've found
that putting in a really long disk and scanning to the end
and back several times helps.

The static sound seems to be a real problem on portables
which tend to stick and have wimpy power supplies...

BTW I've had one bad disk out of about 200.  There was a
small but visible bubble in the polycarbonate.  It caused
the left channel to drop out for about a half second...
I've had several more with manufacturing scum on them...
kind of like glue... which caused them to skip.

FWIW,
R.

    Somehow I don't think anyone is focusing in on the important (and
    really puzzling) detail: a CD that you've played a number of times
    (say at least 6 or 7 times) suddenly begins to have a problem reading
    the opening information so that it will play track 1. I have one
    CD that demonstrated this behavior. I cleaned it thoroughly, I cleaned
    the laser assembly, and I'm sure that the first 6 or 7 plays must
    have included at least ONE in which I didn't seat the disk completely
    on center. But now it has this problem. I don't have ready access
    to any other players, but I can't help thinking that the CD itself
    has, for some reason, begun to deteriorate since I first bought
    it. (By the way -- I NEVER touch the surfaces of CDs; I handle them
    only by their edges, just as I do vinyl records. And I always return
    them IMMEDIATELY to the jewel boxes after playing them. And while
    they're playing, I keep the jewel boxes closed to keep dust out
    of them.) Don't want to be an alarmist, but I can't help thinking
    about those stories of CD rot.
    

    Whether this is a case of a problem which happens with continued
    use or a situation where the problem is only evident on some occasions,
    the problem remains that unlike a l.p whose problems, if they be
    a manufacturing fault, are easily noticed and solved by returning
    the l.p, this situation makes returning the discs a problem. Since
    there is no way of knowing if it is the disc or the player, and
    if some players are more apt to detect/cause problems then r
    turning the defective disc could be a real pain. Especially if
    the defect is not a constant. If for instance you bring back
    a disc that cues up fine on the store player, or if the store
    player is state of the art and reads through errors that your
    home deck does not, you're screwed. I have had people in record/
    c.d shops tell me that "You can tell the quality of the disc by
    holding it up to a light, if you can see the graphics from the other
    side then the disc is cheap and will fault easily" Now I don't
    know about you but this sounds like hocus-pocus bullshit. It
    seems, at least for now, that we are dealing with a product,
    a medium that we are still mystified about. Everyone has a opinion,
    but trying to find two people to agree is next to impossible. It
    leads me to believe, at least on the retail end of the market, that
    nobody has a clue. They sell the suckers, but when it comes to info
    on the product they just repeat whatever they heard last. I don't
    want to be wasting time returning discs that are fine just because
    my "laser is off" and I certainly don't want to pay outrageous
    repair fees to confused repair people because I've bought a few
    defective discs. Comparing a couple decks only works to the extent
    that you can come to the conclusion that one machine will read a
    disc and one will not. I don't think this still anwsers the question
    of if you're dealing with a questionable disc or just varying degrees
    of quality players. If a 600 dollar deck reads the disc fine but
    a 250 dollar deck has problems have you proven that the disc is
    defective or the more expensive unit is over-riding faults that
    the less expensive unit was unable to. These and other question.

    
    
    One thing that I have noticed is a trend in more expensive machines
    for more elaborate error correction algorithms which seems to be
    a response to this phenomenon.  
    
    There's no incentive to add extra circuitry to correct for "marginal"
    discs unless it's been shown that there are enough marginal discs
    out there that the buyer may actually have one!!!!
    
      

    I noticed some static playing my sony d-10 last night. I tried the
    disk on another player, and it does not happen, so the problem must
    be in my player. 
    
    I looked through the limited maintainace section of the manual,
    and it suggested using a "commercially available blower" to clean the 
    lens. Has anyone ever seen or used such a thing? 
    
    Is there anything else I might try to eliminate the static that
    I'm hearing? Or should I try to get Sony to fix it?
    
    thanks for any pointers,
    
    Dennis 

    Many photographic shops sell them, small rubber bladders with a
    nozzle. There are also minature electric vacuum cleaners available
    probably from the same shops or one that sell hi-fi trivia.
    
    Richard.

    You can  also get cans of compressed air at photographic shops. I picked
    up a can at Lechmere's.

    Its easy  to  blow  air  on  the  len  in  my  portable,  since its very
    accessable,  but  my  home  unit is a drawer model, and you can't really
    directly blow air on the lens.

	marty

    I experienced a problem exactly as described in -0.  It was corrected
    by alignment of the laser.
    

I've also had strange problems with my Sony CDP-101 and several disks. Some CDs
work fine in my Alpine Car-player and don't in the home set. This is caused, I
think, by the improved error correction circuitry in newer players (my Sony is
five years old), because of which the quality of the CDs has deteriorated
somewhat, if you hold some discs to the light you will often notice some tiny
holes in the reflective coating, which may cause older players to slip. 

As for the problem of discs that work fine for awhile an then go on unmotivated
strike, this has me puzzled as well. Most of the time reinserting the CD helps,
but sometimes I have tu put in a different CD to get the player to read the
index on the one that didn't work previously. At times, when the player tried to
find the first track for ages pushing the <next track> button miraculously got
it to start playing track two. I suspect there are as many opinions about this
as there are CD-owners around. It's always interesting to hear about other
peoples problems, though.