Playing DVDs in my Panasonic DMP-BD60?

[wilky61]

I feel like an idiot asking this, but I've only had the BR player for a couple months and I tried to put a DVD into it for the first time just yesterday. Didn't work, blue screen and "NO SIGNAL." The display on the BR player was reading a "U72" error, and I wasn't able to learn too much through Google-searching other than that the problem seems to be in the HDMI cable connection. Intermittently, though, it would flash the seconds counter as though it were playing the DVD.

How does this work? Do I need a different HDMI cable? Do I need to use older cables to get my DVDs to play?