quick (but maybe difficult) question

Discussion in 'DVD Video' started by kingrundzap, Sep 2, 2006.

  1. kingrundzap

    kingrundzap Guest

    I've got a Sony DVD RW DW-U12A in a Sony Vaio computer that's a couple
    years old. I know the common answer to the problem I'm having is that
    the drive is going--it won't read any CDs any longer, and it's
    increasingly not reading DVDs. PowerDVD gives me the good old "A disc
    with an unsupported format" message in those cases. I'm only trying to

    read commercial prerecorded discs, by the way--not burned discs. I do
    have AnyDVD and CloneDVD on my computer, though. And even when those
    read discs sometimes, they can't analyze the whole disc--they get to
    about 80% or so and CloneDVD locks up. I've tried disabling and even
    uninstalling both AnyDVD and CloneDVD to see if they're causing the
    problem (because of some other copy protection on the commercial discs,

    maybe), but I have the same problems then.

    Here's my question. Why, if the drive is going bad, can it read a lot
    of discs just fine, but not others, and it's consistent on which discs
    it can read and which discs it has trouble with? It must be something
    about the way the information is encoded on certain discs combined with

    whatever is going wrong, I'm assuming, but what?

    Partially, I'm just trying to make sure that the drive is going bad and

    that it's not some other problem. I don't want to (and can't really
    afford to) spend over $100 for a new drive and it doesn't solve the

    Thanks in advance
    kingrundzap, Sep 2, 2006
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  2. kingrundzap

    JoeBloe Guest

    The laser head is out of calibration or dusted.

    I'd be willing to bet that it will read just fine upside down.

    The heads sag after a time on their support springs.
    The speed at which a burned disc is recorded can affect it's
    "contrast ratio". same number of bits laid down with a non differing
    laser power will produce this. Older writers didn't vary power so as
    write speeds increased, contrast ratio decreases. In other words, the
    pits get laid down by impinging less on the polymer layer, producing a
    more shallow pit, making the difference between a pit and land less
    "apparent". Also, a DVD is read with a different "head" than the CDs
    are, even in the same reader.

    So, it is either a sagging head and turning it upside down will show
    this or it is that you are reading discs that were burned too fast.

    Also, as a burned disc gets older, the pits "burned" in it "relax"
    rendering it unreadable.

    Could be any of those three or combinations thereof.

    and it's consistent on which discs
    JoeBloe, Sep 2, 2006
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