What happens when a dvd player doesn't like the disc ?

[drewzor]

Hi everyone, I would like to know what is actually happening when a (dvd-r) backup of one of my dvds is put into my dvd player. Sometimes but not all the time it will studder and pixelate (large) and even lockup completely. But I'd like to understand why, is it that the laser doesn't access the pits burned into the die? or the processor cannot retrieve the 01010110111 from the laser?

I dont know...

anyone thanks?

[BJ_M]

laser can not read the disk

[drewzor]

is this because of a cheap disc, a poor laser, a poor burn?

[redwudz]

Sometimes the stutter and pixelation you may see could be the players memory trying to display the last readable frame. If you listen to the player, you may hear it changing speeds up and down while trying to 'seek' the track The lens mechanism will also fly back and forth and make some noise. If you let this go on for a few minutes, (Not recommended) and take out the disc, it may be fairly warm. And if you try this about 6 times in a row, your OS will probably reset the drive to PIO mode as it attempts to read the disc. I don't think this happens on standalone players, but it could overheat the read laser or mechanism and damage the player.

I guess you could look at the disc under high magnification and you might see a problem with the burned pits compared to a good disc. I have seen some discs with 'blotches', but that appears to be a problem with the dye on the disc, not the burner.

The burner calibrates itself to each disc inserted by burning a test strip in a special area near the center of the disc. When this fails, that's a 'Power Calibration Error'. I suppose if it misreads the brand and type of disc, it could use the wrong burn strategy for the disc and make a 'coaster' also. Not as common, but dust on the laser lens can make a bad burn, but all burns would be bad, no matter which brand disc was used.

Of course none of this probably explains why one player can read a disc when another can't. Some may be better at reading a poor burn.

I'm thinking there are 'volumes' written about this problem somewhere. These are just my guesses.

[cyflyer]

I don't think this happens on standalone players,

i think she/he probably does mean the standalone player. I think she/he also means that she used cheapo media (which ?) and why does it pixelate ?

[TBoneit]

Why, poor media, poor burn, player doesn't like that media, take your pick.

Tell us what discs and maybe we can help.

Even the same make and model are not always equal. I had two exact same Toshibas bought one week apart. One would sometimes do exactly what you are describing. Sadly for me, I didn't twig to the player being bad until after the warranty period had expired. It played Originals fine. Just not reliable on burned media. Probably something out of spec in the laser is my guess. It always acted up towards the edge of the disc, I use good media, MIJ or Verbatim. I still have it sitting around as I could use it as a divx player for 1/2 full discs I guess and because I'm a packrat. I still have a 20 Megabyte Seagate MFM drive sitting in the basement!

[drewzor]

In this case a Sony dvd-r in a standalone pioneer I bought for $500 in 2001.

I have however seen this happen with all types of discs though, cheap and expensive. Also this particular disc plays fine in the $36 player at work?? Just as confusing, the xbox 360 demo disc which pixelats and locks up in portable dvd players at work plays just fine in the pioneer I have.

Hot Discs and laser shifting noises are spot on redwudz, I might try a jewellers magnifier so see if i can find physical damage. But thanks Redwudz that was very helpfull.

[hech54]

a standalone pioneer I bought for $500 in 2001.

The bigger they are...the harder they fall.
Many of the older Big Name players are notoriously crappy at
playing recordable media....even CD-R's in the case of Sony(DVD) players
from the same era as your Pioneer.