DVD-R Iincopatability?

Maybe some one can help me out with this. I have an LG unit that I can record on and we tried watching the DVD-Rs on a friends Sanyo and also RCA units but, they don't load and play. We even tried our computers using Windows 7 and Windows 8 and the same thing the disc is not recognized.
What I have recorded is very valuable to me is there some way I at least can them transferred (if necessary) so that we can watch them on anything or what seems to be the problem? I could really use your help. Thanks
Thank you , I'll be getting back to you concerning this at a little bit later time.

I did look at some of the specs for the LG players and found that it stated that they won't play on other units because the format is different!
08-07-15: Rsjm80


Please point out where it says that in the owners manual for a DVD-R or a DVD+R disc that is recorded in the Video mode and then Finalized.

LG RC700N owners manual
OK, I have to look, I have been real busy today with a car show, I'll get back to you on that but I found in the specs for one of the new LG units that IT DOES say that the format is different, it may not say that in my manual but I'll check again and let you know.
Rsjm80, After browsing through the manual (thanks for the link Jea48), I don't see any reason why the disc you recorded and finalized shouldn't be a "standard" DVD playable in other machines. The manual even states that at one point. Also, it doesn't appear that the non-standard recording length I mentioned above is even an option on your machine.

One thing I thought of while reading through the manual - if the program you recorded is that valuable to you, you can always use your machine to dub it to VHS. I know this is not optimal because of the loss of some quality but at least you would have the program. I'm also sure that you can find a service to create a DVD from the tape.

Jea48 & Djohnson54, I have searched the manual and cannot find that it states there could be format differences. I did find that in the newer LG recorders though. I even thought that maybe the recording mode was wrong but, the manual says that DVD-R discs always default to Video mode and as such they (in theory) should play in others. That's why it baffles me as to why it won't play on my friend's earlier Sanyo or the newer RCA surround unit. I thought that maybe the format selection might be wrong and be in VR mode but, since the DVD-Rs default I can't be wrong so it only comes down to a format difference then as now stated in the newer models.
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