Sorry to hear about this. Yes, I'd recommend trying a factory reset. If that doesn't do anything, this sounds like it may need servicing. Here's the thread where you can get details on setting that up: http://forums.cnet.com/7723-13973_102-542437/service-issues-click-here-for-help/
I found couple old issues with HDMI ports not working, I'm also having this problem:
I have a Samsung PN63C550G1F Plasma HDTV, with 4 HDMI ports.
HDMI-1 connect to AT&T cable box, HDMI-2 connect to PS3, Component-1 connect to Wii.
Yesterday morning was raining with distant lighting (3 seconds thunder sound delay), and in the afternoon when I turn on the TV and cablebox to watch some shows and nothing happens.
This is what i experimented:
1) TV, Cable Box, Wii, and PS3 all connected to same surge protector (TrippLite ISOBAR),
this TrippLite itself is plug into another surge protector (Belkin) which plug into the wall outlet.
Both surge protectors seem okay, both showed green light for protected and grounded. Both breaker has not tripped.
2) Component-1 (Wii console): works alright, TV display game image and sound just as always.
3) HDMI-1 (Cable box): TV is blank except displaying "HDMI1/DVI 1080i" in the upper-left corner as usual, also display "No Signal" in the center of screen. No Sound.
4) HDMI-2 (PS3): TV is blank except displaying "HDMI2 1080P" in the upper-left corner as usual, also "No Signal" in the center of screen. No Sound.
5) I power-off everything, Unplug and plug in all cables: power, HDMI, Component.
It's still the same: HDMI ports 1~4 does Not work, "No Signal", no image, no sound.
Component port works perfectly.
6) I plug the Cable box [Audio Out] (Red/White ports) to a boombox and I can hear the sound from the TV shows, so the cablebox seem okay.
What is "factory reset"? I read in other posts: Hold Exit button on remote for 20 seconds.
Should I try this?
What else can I do?