Well, it seems like you either looked through the forums, or spent a lot of time troubleshooting (or both!). Normally I'd think that "Searching for Signal" or "Not Supported Format" would be a resolution issue, but since you've tried that with no success, I have to admit that I'm stumped by the outcome. HDMI-4 may be an independent input - just a thought, though I'm unable to confirm that of course.
What I would suggest is having the unit serviced. Since it's a B-Series, that indicates a 2009 model, and you're likely under warranty still. I would definitely recommend registering your product online (which gives an additional 3 months of warranty coverage for U.S. customers), and then calling in and seeing if you can have your unit inspected and repaired.
If you'd like to try a home remedy situation, with the TV on, hold down the EXIT button, and you can reset your television to factory defaults. I would note, however, that if you had your television professionally calibrated, those settings will be gone.
Keep me posted.
I'm hoping Anthony or any other forum member can provide some insight into my problem.
Here is my setup:
Samsung LN40B630 (Latest firmware)
Playstation 3 (Latest firmware)
Homebuilt PVR w/ MS Media Center
If I try to plug the PS3 or PVR into HDMI inputs #1, #2, or #3 I see "Searching For Signal" for a brief second then the it changes to "No Signal". Input #4 works with no problems at all.
Even stranger, if I plug the PS3 into #4, and the PVR into any other HDMI input, the PS3 output can be seen on both sources. It's as if it believes the single input is plugged into multiple ports. (vice-versa and the sources behave the same way)
Here's a kicker, everything worked fine for the last 3 months and this problem just surfaced today.
Here's my list of ideas tried thus far with no success:
Replace HDMI Cables
Reset output settings on the PS3
Reset output settings on the PVR
Reset video settings on the TV
Turn on/off TV and sources in various orders