Thank you for posting your question on Just Answer! I will be happy to help you with this problem. Can you please give us some more information so I can better answer your questions.
-If you turn a screen control up, do you get anything on the screen?
Please give me this information and I will be happy to assist you further.
You need to find the focus block, it is a square block with 6 knobs on it, normally mounted in the front of the tv. 3 of the knobs will be for SCREEN and 3 for FOCUS. you need to turn one of the SCREEN knobs up a little and see if anyhting shows up on the screen.