Self Correcting Dvd?

vbimport

#1

Anyone have a “technical” explanation/confirmation of what happens?

I successfully burned a Ridata x4 dvd+rw twice. On the third burn I got a bad record 3.5 hours into it but the standalone kept burning for the remaining 2.5 hours.

On playback, the machine(s) will just stop, freeze, then crash at 3.5 hours. I looked at the disk and there was a matchhead size dark spot. I assumed this was a patch of bad dye and the disk was no good from 3.5 hours out.

I kept using the disks for short records but on occassion it would run long and hit the spot with the same effect.

NOW–I just used the disk and purposefully overrecorded in order to get the exact time to the bad spot for better usage and amazing the disk is working perfectly ok now and the dark spot is no longer there.

Now I’m wondering if the dye spot was bad OR if the recorder put down a patch of overburn or whatever???

Anyway, I’m going to go back thru my spindle of bad dvd=rw’s and see if any others will auto-heal themselves.

Anyone “know” what “technically” probably happened??? Thanks.


#2

This is pretty typical behaviour for RW discs. Very unpredictable.


#3

It could have been the phase change layer could have been stuck which caused it to be in one phase mode and not able to switch at that time for a time. Temperature changes could have caused it to work correct again.
This autoheal behaviour is typical behaviour for RW disc’s.


#4

I (think) I’m noticing that quite a few of my rw’s that had sticky spots are now writing perfectly===almost like they needed to be cured???

These are rw’s that work perfectly on my Liteon but have 1-2-3 sticky (failure) spots on my ILO unit = but now they are almost all working “as desired” meaning perfectly.

I also put a fan on the external case of the ILO making it cool to the touch. So many variables==hard to tell what you “actually” need to do to get everything working the way it should.

What makes the ILO so HOT? Burning a disk doesn’t create that much heat in the computer or with the Liteon===maybe a hot power supply?


#5

Maybe this has something to do with an automatic defect prevention system called “Mt Rainier”, which is included in the DVD+R standard… Not all drives seem to support it though.

It’s much like the S.M.A.R.T. system in the hard drives.

Read more here: http://www.cdfreaks.com/article/113


#6

Thanks for that Dempsey==read it twice and there is still too much good info there to digest.

I’d like to know some of the same stuff for dvd-ram. If the cost of manufacturing and of the materials is the same==why are they more expensive?? I’ve heard both statements made–can’t confirm either one. But thats off topic.

Mt. Ranier self correcting might be in the recording and playback of the disks???===but what I’m seeing is the color of the disk change from an obvious big black splotch that causes a stall but after several overrecord sessions, the splotch goes away and the disk is then good. The subject disk is still recording well. Not true with some of my other dvd+rewrieables.

I wonder what the “real world” life of a rw actually is??? What with scratches from normal correct usage and random splotches appearing and disappearing, I very much doubt it is in the 1000’s as advertised.

Keep those cards and letters coming. Knowledge is power. /// bobbo.


#7

DVD-RAM discs use different materials and construction than run-of-the-mill DVD+RW. Radically different.

Manufacturers usually quote “up to 1,000” rewrites which usually means “under ideal conditions, this is what is theoretically possible”. DVD-RAM is rated for 100,000 (except 5x and upcoming 16x dvd-ram, which are only rated for 10,000 rewrites). Also I bet cartridge and cartridgeless discs would be affected differently.


#8

Thanks Bastard==

The bit of web surfing I’ve done about the differences between ram and +/- dvd don’t mention any difference in construction other than concentric tracks verses one continuous track and they do mention plastic disks and vegetable dyes which is just like dvd’s??? so I was too quick to assume too much??? How “exactly” are they different then??

I did read on the web that the 100K rewrites for Ram disks was for those that were in a cartridge and that their life was the same as dvd’s for non-cassette/cartridge use which is all I have ever seen ((ie in the last month at Best Buy)).

Do you know if Ram is significantly more reliable in capturing tv during recording and that the disks are not defective so that the extra money is worth it??? Or does it just offer the hard drive type performance but only when they work???

Thanks.////bobbo.


#9

See here:

http://www.dvddemystified.com/dvdfaq.html#4.3.4.2

http://timefordvd.com/tutorial/RecordableDVDTutorial.shtml


#10

Self healing? Halleluja!
This might be part of the administrations faith-based writing strategy. :wink: