Matthew Moore wrote:
On Tuesday June 16 2009 12:41:31 am AG wrote:
Yes - it loads data disks just fine and also DVD disks that I have burnt
myself. When testing it using k3b to burn a DVD, k3b locates the disk
immediately and burns successfully. All other USB drives show up fine.
As the sole user, I have permissions to load CD-ROMs and as far as I can
tell I am a member of all of the relevant groups.
Gnome has an easier time than Xfce4 in picking up that a disk has been
loaded (i.e. an icon pops up on my desktop in Gnome, but nada in Xfce4).
It is because of this inconsistency that I am confused: if it was
completely dead - I'd be looking for a damaged drive/ disconnection. If
no audio-CD player found it, I'd be wondering about permissions; if
nothing worked (i.e. no data disks, etc.) then it may be related to
something else. But, because it can automount data CDs and home-made
DVDs, burn disks fine and that Gnome not Xfce4 picks up the icon, and
that only Rhythmbox can play the disk that I am so confused by this.
Does it always flawlessly read DVD's? I am not sure if this is the case
anymore, but back when the combo drives first came out there were separate
lasers responsible for reading DVD's and CD's. Suppose that the laser for
reading CD's is slightly damaged. Perhaps short data bursts read okay, but
prolonged transfers get corrupted. Some applications may be more resistant to
this corruption (rereading or doing some kind of ECC on the signal), so some
applications may successfully read and some may not. Occasionally failing to
read the TOC/metadata may also prevent it from getting automounted by the
system.
All of this is pure conjecture, but if I were you, I would try getting my
hands on another SATA CD/DVD drive and seeing if you get the same symptoms. If
you get the same symptoms, check to see if the SATA drive is attached to a bus
all by itself. If this is the case, you could have some kind of MB failure on
that bus and switching the SATA channel may fix the problem.
I
mean, what is with kscd reading the track info but then telling me that
it cannot play the disk because there is no disk loaded in the player -
how does it read track info then?
Well, if the track info is written to the CD-TEXT section of the audio CD,
then it could be that the drive is having trouble getting to the rest of the
CD. If your CD does not have CD-TEXT, then it is probably getting the info
from some cddb server. This only requires the TOC information, which is also
written at the start of the disc. In either case, it could be a problem
reading the rest of the CD. Perhaps you should try transferring a bunch of
data from a CD/DVD and md5summing it to see if there is some kind of
corruption going on.
MM
Matthew
Thanks again for replying.
I am not questioning your logic, because what you say makes good sense.
I am doubtful of your diagnosis for two key reasons - one, when I bought
the machine it (of course!) came pre-loaded with a well known
monopolising OS and before I installed Debian I tested the drives with
an audio CD knowing that if there was anything faulty, the shop (a well
known monopolising chain in the UK) would reject my complaint on the
basis that it was the (Debian) software I had installed and not the
hardware. The drive worked fine and again, because I installed the
basic set up for a net installation using a DVD I had burnt using the
same machine the drive is to all intents and purposes fine in terms of
laser read/burn capabilities. Second, if the drive itself were faulty,
I don't know how rhythmbox would be able to play audio CDs. But these
are complex issues and way above my simple understanding, so whilst what
you say may be conjecture, what I am replying is based on poor knowledge
and is hence speculative at best.
As for controllers ... I can't say. It may well be wise to see if I can
get an alternate DVD/CD-RW just to be sure and to eliminate this as an
option, but at this point in time, I'm not holding out much hope.
Firmware - don't even know where to start there - but wide open to
suggestions on how to proceed. Ditto on md5summing data I drop onto a
disk in the drive, as I haven't done that before and don't know where to
start md5summing something (i.e. setting it up).
As a way forward, I will buy a sata DVD/CD-RW, install that and fire up
the system again. Who knows - I may luck out and just have a dud drive
in which case I will be a happy bunny. So, to be fair to you and others
on this list, before taking up any more time I'll go down that route
first and report back.
Thanks for your continued suggestions. I'll give an update in a day or two.
Cheers
AG
