Hello,
Pdp stands for "plasma display panel"
It does seem like you could have a problem with that however there are other things that could be bad as well, might want to take it in and have it looked over to find out the exact problem, as some of these can cost just as much, close to or more then just replacing the unit with a new one.
Thanks,
Joe
Technician
ASE cert tech for over 12 years, electronics has been my highest study, 4 years of home electronics