3,442 PO Failures! Yet, still copies back!

vbimport

#1

Originally burned using a LiteOn SOHW-812SX external burner.
Media: Fujifilm 8x DVD-R ( FUJIFILM03 )

Was bored so I loaded up the Benq 1620 to scan some old burns from that LiteOn. When i saw all those nasty PO Failures, I had to see if I could copy it back to the harddrive - let alone be it readable.

Amazingly, the files copied back (took forever though) using a SONY DVD-ROM DDU1611. I would’ve never thought based on a quality scan like that the data could actually be salvageable. Thank God it copied back b/c I lost the original DV’s of the videos we took on vacation!

Man, I’ve read the LiteOn’s don’t do well on -R media, but this is ridiculous. I hope the rest of my vacation DV backups don’t turn out quality scans like this!! Freak!! :a


#2

I’ve had the same results with some Ritek G04s that went south after a year. Amazing what some readers will do. :clap:


#3

A POF doesn’t mean unreadable… there are still ways to read back the data for example if the drive slows down to a lower speed… and retries, retries, retries,… =)

I would suggest that you check other discs also… and now burn 2 copies (on 2 different discs) just to be on the safe side as I guess the video is very importaint to you and it would be a shame if you’d lost it. By burning 2 copies you halve (or even more) the risk of data loss.


#4

lets hope people will stop s***ting their pants at 10 PIF spike after seeing this…


#5

Yes, I agree - except with the risk calculation.

If the possible causes for two discs “A” and “B” going bad are completely independent of each other, then the probability of both discs going bad is the product of the individual probabilities; e.g. if there is 5% chance of disc A going bad and 4% chance of disc B going bad, and the causes are completely non-dependent, then the probability of both going bad is 0.05*0.04 = 0.2%. So the risk is significantly lower than half the original risk!

If the causes of failure are not independent however, like A and B being the same batch of discs burned in the same burner and exposed to the same environment, then the risk of both discs going bad could be as high as the risk of only one of them going bad!

This is why you should burn on different batches of media from different producers and then keep the two copies in separate locations!


#6

All very excellent suggestions. Appreciate that, and they may just have saved me from disaster in the future. :slight_smile:

@chas0039:
I definitely have more confidence now when I experience “lesser” quality scans. The main caveat being the media being used and its longevity (thank goodness for scanning tools!!).

@Quikee:
Thanks for the suggestion. I’m definitely going to dig up all the dvd’s I’ve burned previously and scanning each one. There will be some mad burning sessions in the near future. Hope this Benq holds up … hehe ( that comment was for chas0039 :slight_smile: ).

@MrQQ:
I agree with you now that I’ve seen this horrid quality scan can still be readable. I guess the other variable is if there are CRC errors, then I’m toast (at least for that clip that can’t be copied back).

@DrageMester
From now on, everything gets at least double burned and triple checked. I like the suggestion of storing them in different areas.