I have a Hitachi 19WDVBDVD tv dvd combo, bought it 4 weeks ago and it isn't playing dvds.

DVDs were playing fine earlier, 1 froze so i stopped it and ejected it. I put it back in and it just says it's loading but does not play. I ejected it and tried a dvd that worked earlier and again it said it was loading. Now it won't even eject.

I don't have the manual just now, are there any simple things I could do just now that may solve problem?

 Thanks