I have a Sharp DV-SL20U DVD player that plays CD's but doesn't recognize
DVD's. I've cleaned the lens and determined that the laser is working. Can
anyone help bring this back to life? Thanks.

"Greg Laux" wrote in message
...
I have a Sharp DV-SL20U DVD player that plays CD's but doesn't recognize
DVD's. I've cleaned the lens and determined that the laser is working.
Can
anyone help bring this back to life? Thanks.


Failure to play one media type, particularly the way round that you have ie
plays CD but not DVD, is usually due to a defective laser. As a matter of
interest, it is very rare to have any problems related to dirty lenses, on
DVD players. This is because the rotational speed of the disc is so high
compared to CD, that a significant drag wind builds up under the disc, which
keeps the lens blown clean of dust deposits.

Arfa

Hi!

This is because the rotational speed of the disc is so high
compared to CD, that a significant drag wind builds up under the disc,
which
keeps the lens blown clean of dust deposits.

That's not always true. Compared to a simple audio CD player, you're right.
However, any computer CD-ROM drive, CD burner, or even a CD player designed
to use digital audio extraction will spin as fast or much faster than a DVD
playback drive.

Besides, doesn't moving more air across the pickup just result in more
stubborn dust appearing? :-)

William

"William R. Walsh" wrote in
message news:xOMGf.787318$xm3.291891@attbi_s21...
Hi!

This is because the rotational speed of the disc is so high
compared to CD, that a significant drag wind builds up under the disc,
which
keeps the lens blown clean of dust deposits.

That's not always true. Compared to a simple audio CD player, you're
right.
However, any computer CD-ROM drive, CD burner, or even a CD player
designed
to use digital audio extraction will spin as fast or much faster than a
DVD
playback drive.

Besides, doesn't moving more air across the pickup just result in more
stubborn dust appearing? :-)

William


Hi William,

not in my experience. In many years of attending to DVD players - since they
first appeared, I don't think that I can ever remember seeing a dusty
pickup, like you often see on CD players, or any playability problems being
cured by cleaning a lens, which they of course often are on CD players. I
was originally told the ' wind under the disc ' explanation by a Toshiba TLO
on a training course he was giving, so believe it - or not, as the fancy
takes you. Always seemed like a reasonable proposition to me.

You are of course correct in that computer CD ROM drives spin the disc up at
very high speeds, but the fact that the drive is pretty much closed in means
that they don't really get dusty anyway, and like DVD drives, they never fix
by cleaning ...

None of this alters the fact that the OP's laser is still likely to be
faulty d;~}

Arfa

Dust sticking depends on where you live . I dont see as much dust on a
DVD lens but i have seen it . The climate is usualy very dry here and
dusty . Dust sticks to the sides if furniture etc. far worse than i saw
when i lived in a damper overall climate .
If someone has a dirty house with carpet and dogs or kids the dust is
un-controlable inside electronics here not to mention smokers film ,
poor cooking or fireplace or oil heat ventilation .
Here i have fixed several dvd by cleaning the lens . This inclused PS2
units which kids mostly keep on or near the floor that suck in all the
dirt .

I have determined that the laser works by putting in a transparent disc and
looking at the laser through the disc while it searches for the dvd info.
The laser is on. Any other thoughts?
-Greg
"Arfa Daily" wrote in message
...

"Greg Laux" wrote in message
...
I have a Sharp DV-SL20U DVD player that plays CD's but doesn't recognize
DVD's. I've cleaned the lens and determined that the laser is working.
Can
anyone help bring this back to life? Thanks.


Failure to play one media type, particularly the way round that you have
ie
plays CD but not DVD, is usually due to a defective laser. As a matter of
interest, it is very rare to have any problems related to dirty lenses, on
DVD players. This is because the rotational speed of the disc is so high
compared to CD, that a significant drag wind builds up under the disc,
which
keeps the lens blown clean of dust deposits.

Arfa

"Greg Laux" wrote in message
...
I have determined that the laser works by putting in a transparent disc and
looking at the laser through the disc while it searches for the dvd info.
The laser is on. Any other thoughts?
-Greg


Being able to see the laser burning, unfortunately does nothing to prove
that the optical block overall is working, as it contains the pickup(s) as
well. Also, being able to see the laser burning, tells you nothing about the
output power of the laser. This is critical to correct operation of the
optical block, and the following circuitry. Trust me, the lasers do wear
out, and failure to play one media type, usually DVDs, is a very typical
symptom

Arfa

"Greg Laux" wrote in message
...
I have determined that the laser works by putting in a transparent disc and
looking at the laser through the disc while it searches for the dvd info.
The laser is on. Any other thoughts?

Yes. Stop looking at laser beams! Seriously, though, an imperfect
transparency might offer enough diffusion so as to decrease the danger a
bit, but it's still not a bright idea [pardon pun] to look at it.