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Author Topic: Disc errors when booting latest TC release from a CD  (Read 19888 times)

Offline coreplayer2

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Re: Disc errors when booting latest TC release from a CD
« Reply #45 on: September 07, 2011, 08:26:31 PM »
I get these errors whenever booting tc with a cd/dvd in the drive.  same results but not consistently with commercial disks or cdr.  am going to revisit this issue asap

Offline cast-fish

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Re: Disc errors when booting latest TC release from a CD
« Reply #46 on: September 11, 2011, 07:50:26 AM »
Blanking a re-writable CD before burning is probably a good idea.

Ru and Rich,

i have not actually tried burning TCL again just yet. But i will give it a go soon because
i don't like seeing those errors.

Ru was saying that his CD recording tool always defaults into the max speed
that a CD RW disc will support. Mine is similar and i am not sure if that speed
can be altered.

I will have to burn the CD from the Linux desktop and issue the command that
Ru has mentioned in this thread.

It looks pretty likely that my situation is similar to others in this thread...it's a badly
burned CDRW disc.

Having said this, i have been burning distros for 8 years and this has never happened
before ever. Even with this same hardware, but  ofcourse, different media discs each time.

Just a note on this kind of topic that i am sure you are all aware of. Cheap blank CD discs can loose
the optical burn for no reason. It tends to happen after leaving the discs in darkness for a few weeks. They
gradually loose the optical burn and eventually fail to run. Externally the disc looks perfect without any
scratches or such like. You can't guess it's a faulty disc....you just eventually realize. This can be
tricky when you have already been successfully using the said "burned disc" for weeks.

V


Offline Rich

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Re: Disc errors when booting latest TC release from a CD
« Reply #47 on: September 11, 2011, 11:58:54 AM »
Hi cast-fish
Quote
Just a note on this kind of topic that i am sure you are all aware of. Cheap blank CD discs can loose
the optical burn for no reason. It tends to happen after leaving the discs in darkness for a few weeks.
Nonsense. CDs are not sensitive to the presence or absence of light. Temperature extremes might
cause you problems. Heat generated by the LASER beam in your CD drive changes the reflectivity
in the disc by altering the color at the points you are writing to. So if a blank disc has all zeros, the
LASER heats the points where you want ones. CDRWs are the same except power levels, heating,
and cooling time are more critical. It is because of this last point that CDRWs also have a minimum
write speed. I have some 24x CDRWs, the minimum write speed listed on the package is 16x.


Offline cast-fish

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Re: Disc errors when booting latest TC release from a CD
« Reply #48 on: September 11, 2011, 02:20:54 PM »
in that case Rich, is it possible that a CDr disc can have scratches
that are not visible by the naked eye, but scratches that can make the disc optically non readable?

V.


Offline bmarkus

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Re: Disc errors when booting latest TC release from a CD
« Reply #49 on: September 11, 2011, 02:25:58 PM »
During last 20 years I have never seen CD's degrading in time, but have seen faulty, unrealible discs due to faulty CD writers having very short lifetime.
Béla
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Offline Rich

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Re: Disc errors when booting latest TC release from a CD
« Reply #50 on: September 11, 2011, 02:32:02 PM »
Hi cast-fish
I can't rule out the possibility, but I think it's unlikely. I had an old CD drive that was a bit hit and miss
when it came to burning CDs. After opening it up and carefully cleaning the LASER diode with cotton
swabs and alcohol it behaved normally again.

     [EDIT]: Before the cleaning it was also a bit touchy about booting CDs.
« Last Edit: September 11, 2011, 02:35:15 PM by Rich »

Offline cast-fish

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Re: Disc errors when booting latest TC release from a CD
« Reply #51 on: September 11, 2011, 02:38:39 PM »
Hello,

ah, so are you saying that an "older burning drive" could potentially begin to start creating
faulty burned discs and those discs "may or may not" continue to be effectively "readable"
in that drive...?

is there also a case, where a CDr disc that is burned in drive "a" also gets perfect
"reads" in drive "a" but may not be readable in other drives?

V.

Offline cast-fish

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Re: Disc errors when booting latest TC release from a CD
« Reply #52 on: September 11, 2011, 02:49:34 PM »
yes rich

this is a hunch here. (could be gobley -gook ....but)

is it possible that "burning drives", like you say, can be temperamental.

Say for example, you burn a CDr disc with a Linux OS. Right away you
start reading that disc in the same drive and things are fine.

Weeks go by where you don't read that Disc. But also, you don't use the drive
to do any burning, just reading of other discs. The heads in the drive get dirty.

Later on you try the same Linux disc in the same drive and it fails to be "readable". You throw
the disc away and immediately "burn" a new disc using the same drive. But the burning process
somehow cleans the internal drive heads...so the drive now correctly reads the recently
burned disc.

V.

Offline Rich

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Re: Disc errors when booting latest TC release from a CD
« Reply #53 on: September 11, 2011, 03:06:24 PM »
Hi cast-fish
In response to Reply#51
Yes and yes. If the LASER is weak or dirty it may not generate enough heat to write the bits properly.
By slowing the writing speed you can sometimes work around this, at least for a while. That's because
the disc spins slower and the LASER has more time to heat each bit.

In response to Reply#52
If the burn is marginal, anything can happen. A one may look like a one or a zero from one day to
another or one drive to another.

I think we've been off topic long enough on the inner workings of CD drives.

Offline gadget42

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Re: Disc errors when booting latest TC release from a CD
« Reply #54 on: March 02, 2022, 03:43:12 AM »
I think we've been off topic long enough on the inner workings of CD drives.

@Rich: perhaps this thread could be retitled to "inner workings of optical drives"
(since the current title is rather generic/non-descript)

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Offline Rich

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Re: Disc errors when booting latest TC release from a CD
« Reply #55 on: March 02, 2022, 07:17:03 AM »
Hi gadget42
Since the point of the thread was not about the inner workings of optical drives, I came up with this instead.