A little too high a temperature and the common DVD recorded media could appear blank. I usually try a new DVD drive but given you tried other machines it looks like this content is gone.
We have several DVDs of home movies. They are Sony and Memorex DVD-Rs. They were burned a couple of years ago, and we have watched them at different times since then. However, we recently tried to watch them and they appear to be completely empty. We tried different computers and players and they all say the discs are empty. There is no available space on the discs, but there is also no data. Any suggestions on what could have happened and possible recovery?