dvdrw usually says "no disc" [solved]

[nordic bro]

I have a jvc dvd player hooked up to my tv. it plays burned dvd+r/-r, vcd/svcd and older dvd+rw just fine. I have a newish box of verbatim dvd+rw that often cause "no disc". it's the same brand/speed as the older dvd+rw which all play fine.

what happens is I'll insert a problematic dvd+rw into the tray, close tray and player starts to play it often but sometimes will get "no disc" instead. whether it worked or not initially, if I power down the dvd player with the disc in it and come back later I'll almost always get "no disc". if I cycle dvd player power on/off a half dozen or so times I'll continue getting "no disc" until it finally starts to play the disc.

the trouble seems to be the discs themselves and I'm wondering if there's anything I can do to fix this? I realize I could get a new box of discs but since I don't understand mechanically why these cause "no disc" the replacement discs could cause the same trouble.

I've tried 'dvd+rw-format -force' a couple times which gets them to start working for awhile but if I understand, formatting greatly shortens the life of dvdrw.

so instead of format I've been using 'growisofs -Z /dev/sr0=/dev/zero' at times which may or may not help stop "no disc".

does anyone know what either of those two do to the dvd+rw itself that can cause "no disc" to stop temporarily? because I'm wondering if there's something else I don't know about that I can do to essentially 'recondition' these discs so they'll be less problematic?

[szatox]

Just a guess, maybe those DVDs are simply old or were stored in bad conditions?
It happened to me a few times to find empty CD-R no longer writable a few months after I bough them, even though others I burned immidiately and they were fine.

[nordic bro]

thanks for the reply. actually all of these burn ok. it's weird because you'd think if the player doesn't recognize there's something in the tray, cycling the power over and over shouldn't help should it? because if I cycle the player enough times until it finally recognizes something's in the tray it will play it just fine. it's very rare I've ever had to do that for any other disc I put in it. I thought it might be a laser alignment issue but I have pioneer and samsung burners and have the same player trouble no matter which I use.

I did check the dates on them and it's the same year on the box as a couple other good boxes of dvdrw I've been using for quite awhile w/o any probs. could it be something about whatever identification area optical media has on it so that a device knows there's something in it? does anyone know if there's a way to test that? I've used dvd+rw-mediainfo and afaict these discs report just like my other dvdrw but aren't sure what I'd be looking for.

[nordic bro]

cleaning the jvc player lens with alcohol and fiddling with the lens positioning gear seems to have fixed this. I had gotten another of the same verbatim brand/date dvd+rw packages and was surprised to see "no disc" on those too. if I opened/closed tray or powered player off/on enough times it would eventually recognize something was in the tray and play it.

what seems weird is that nothing else did this, only the 'newest' (same label date as the good dvd+rw) and the replacement package I got. hard to imagine it could've been a lens issue but looks like it was.