If I were you the first thing I would try is another HDMI cable. I know you mentioned that using your current cable with your TV/PC monitor works but since the cables are relatively inexpensive I would try a new one anyway. Make sure that the cable meets the specifications for the TV (HDMI version 1.3 I believe).
Good luck . . .
Hi. I have a Samsung 40'' LE40r87BD television that seems to work perfectly; except, that is, through my HDMI cable which is attached to a cable TV box. All i get is a black and white picture. Video and DVD pictures via scart lead are fine, brilliant even, all in glorious colour. But...HDMI pictures are monochrome. I've been through all the settings on my TV and they look OK. It's only when I switch to HiDef in the Cable settings that the problem occurs. Cable company has change the STB three times all to no avail and have decided the TV is at fault. I called Samsung and they say it isnt. Funny thing is, if I connect the HDMI cable to my TV/PC Monitor the picture is fine. Is there anyone out there who can figure this out before I jump off a tall building.