DVD+RW compatibility problem

Are all DVD players/recorders supposed to read all previously recorded DVD+RW discs, regardless of which machine originally recorded the +RW and which manufacturer made the +RW media? Here's my dilemma, stemming from an ebay problem, but I'm posting it here because I'm looking for any technical info regarding DVD rewritable media:

I sold a Sony DVD recorder/VCR/digital tuner combo to someone who says the unit he received from me is "defective" because it won't load and recognize his library of DVD+RW's, which he had previously recorded on some other unit(s). He says that the Sony he bought from me works with all other media (DVD-R, etc.), but since he has a huge stack of +RWs, this is what he mostly cares about (the Sony unit I sold him does state +RW as a usable format).

However, the Sony manual also points out that rewritable media recorded on other units might not work on said Sony unit, inferring that there's a simple rewritable incompatibility problem between discs burnt on different recorders, but this guy can't seem to grasp that at all, insisting that because the machine is featured as being able to play/record +RW's, it therefore should be able to play all +RW's, no matter which other machine or computer DVD drive did the original burning.

I asked him to put a blank +RW into the Sony machine, and voila -- it recognizes the blank disc and will burn and play it. That should have convinced him the Sony is not defective. Nevertheless, he brought the Sony to some local old school video equipment repairman, who, he says, apparently agrees with him that the unit must be defective -- because it won't read the old +RW discs which had been recorded on other units. (The buyer also revealed to me that he owns three other DVDR/VCR units which don't recognize his library of +RW discs -- those other units must also be defective, he maintains. My Sony unit, apparently, is merely the latest "defective" unit he's gotten which refuses to play his +RW media.)

Though I've already agreed to give this customer a full refund if he returns the unit, he expects me to reimburse him for cross-country return shipping, citing his repairman's opinion that the unit is "defective."

I know the real issue is incompatibility between rewritable media recorded on different DVDR units -- probably a different manufacturer's unit. A DVD+RW recorded on a Philips DVDR might not play on a Sony, or vice-versa. Or a DVD+RW recorded on a Sony recorder manufactured in 2002 might not play on a Sony DVD player manufactured in 2011. What are the technical issues behind this? Proprietary bitstreaming? Different codecs?

 

You've answered your own question....the manual said some RW discs made on other equipment may not play on that unit. I don't know the technical reasons why not, but it was a valid warning. I've had players that were very picky on the discs they would read....even blank discs of the stated usable format. I've got a Panasonic dvd recorder that almost always rejects any TDK discs I try to finalize...and an LG recorder that doesn't like dual-layer discs other than Verbatim. The guy said the Sony reads and records blank RW discs. Nothing defective about the machine. His repair guy doesn't know much either. So....it's not your fault and you are being nice allowing a refund of the unit. Personally I don't think you're responsible for the return shipping, but that depends on how much nicer you want to be and how much of a stink he's going to make about it.

 

This is a fifteen-year-old problem. DVD+R and DVD+RW formats came out of Sony & Philips' desire to make video discs "more compatible" with DVD-ROM players. For various reasons, some DVD-R recordings were slightly dodgy with certain DVD-R drives. They changed the recording technique to make compatible recordings that had certain advantages, but required a new type of disc:

http://en.wikipedia.org/wiki/DVD+R

I made DVD-R and DVD+R recordings pretty much from the moment the machines were first available, right around 1998-1999, and rarely did I ever have a problem making a disc that couldn't be read by all the players I had access to. But the rewritable DVD-RW and DVD+RW formats were always, always flakey to me. I don't think the chemistry works as well, and I encountered a lot more data errors, tracking problems, and "premature ejections" from players during that era. To me, all the RW formats are lousy. (And that includes CD-RW.)

The only rewritable disc format I've encountered that really works is BR-E, the Blu-ray format, and it's pretty robust. DVD-RAM was also very good, but it's been dead for a long time and was never very widely supported. I would tell your customer from me: stop using DVD-RW and DVD+RW discs. It's a lousy format. DVD-R discs are about 10 cents a piece now -- they're as cheap as floppy disks were in the 1990s. DVD-R is a much, much more reliable format.

I would add that all optical disc formats are dying fast and are going away, but that's just my opinion and observation about consumer electronics in general.