Have blank screen with sound. Flashlight test shows writing etc. Says cable not hooked up when it is. When HDMI cable is hooked up it shows up.

Is your computer connected via the HDMI cable? If not pull up menu and change to another input type. If it is HDMI, check cable ends. You can test by plugging into a Blue ray player and see if video plays on monitor as a test method to verify video coming from computer incase your video card has died for some reason..
Your monitor is going into sleep mode since it can not see an HDMI signal coming across the input. Check your cable though.. sounds like the biggest culprit to me.

Most of these TVs show a blank screen unless they are receiving a sinal?

New 48" TCL tv. Hooked into cable box via hdmi cable from hdmi 2 per instructions. Problem is no sound. Screen looks great volume bar shows volume etc. Any ideas before I take it back to SAMs.

try to adjust your resolution to the highest level, ps3 is a very high grapics device..

thanks.

Most laptops have a "toggle":
* output video only to internal LCD screen,
* output video only to external HDMI port,
* output video to both internal & external.

Set the "toggle" to the best value.

The power supply-inverter board is probably at fault. Remove the back cover and locate the standard ac power cord connector. The board that the power input connector is soldered to is your power supply - inverter board. Check the electrolytic capacitors on the board. They probably went bad. A visual inspection is usually enough to find out which ones are bad. They will be either bulging or cracked at the top and leaking fluid. I usually replace all of the capacitors that have the same rating whether they look bad or not. Will save you another repair later. If the caps don't look bad, you can take the board to your local tv repair shop and have the caps checked with a esr tester. It's more accurate and they can be tested with the caps in place. Hope this helps.

i have samsung 22' lcd series 4 tv but i connected it with the dvd player via hdmi it shows mode not supported. but the same dvd works very well on another samsung lcd of same configuratition. please help me

your HDMI output is bad

Hold the power button (5-10 SECS) when turning it on and your PS3 will automatically set the correct video output.

if ur setting up the HDMI cable dont check all the resulusions just check the 1080i coz 1080p is to high for your TV thats why you have that blank screen for 30 sec.