If you know exactly how many hours are registered on the panel, it's likely that you've gone into the service menu. If you've done something in there that caused the remote to stop working properly, or have changed regions or done a number of things, that may be the cause. In which case, it would likely require a technician.
You can try, with the TV powered on, pushing down the MENU button on the remote until it prompts you to "RESET", to which you might try selecting YES to see if that helps.
Not to be a wise guy, but have you tried fresh batteries?
I'm starting to have problems with my Samsung PN50B650 plasma television. Twice now it has become mostly unresponsive to the remote control that came with it. I can turn the volume up and down, but navigating the menus is extremely difficult (if I'm lucky, holding a button down for a second or two will register a response) and I can't turn the tv off without touching the power button on the tv. When this is happening, the red light on the corner of the tv is flashing on and off. I've also noticed it will sometimes end a slideshow or scrolling bars that I've left up without me hitting anything.
From the beginning, I haven't been able to get the television to connect to the internet, which probably was a bad sign to start off with. I only have 923 hours on the tv. Will I have to get the tv repaired or is there something else I can try?