Is this drive able to read DVDs?The disc cant be burned ....
It's possible that either the DVD drive is going bad, or the media you're using aren't of the highest quality.
First thing I'd try is a different brand of DVD media. If that doesn't work, it's likely the drive is going bad. Depending on which Mac you own (you didn't specify), it can be super easy or super hard to replace the drive.
Is this drive able to read DVDs?