DVD drive not recognizing DVD’s

About six months ago, I bought an internal Samsung DVD drive for my P4 2.65 Ghz home PC. I had to get another one as it didn’t recognize DVDs. The new one doesn’t either. Other things intervened and I didn’t pursue it, as it DOES read CDs, so i wasn’t any worse off. But I still want to use for the original intended use. I download new software from the company website and also did a BIOS reload, but no joy.

Anybody have any ideas? The company from which I purchased it would only test it if I paid $40+ for them to do so. Don’t want to do that.

Thanks,
Michael Fox