My Name is XXXXX XXXXX i am sharp authorized servicer.
I need some more information on the set to provide a clear picture of your error.
What is the model number of the set it should be like: LCxx$xx
The LC stands for Liquid Crystal so all Sharp LCD begin this way.
the first xx is the size of the set so a 50" would be a LC50$xx
The next $ is the chasis type the common run is D which is a consumer number.
The final number is XXXXX model indicator and it can be any number between 1 and 999
A common model is a LC32D62 this is a Liquid Crystal 32" D class model 62
If you can provide me the info it would be of great help to identify your failure.
Sharp televisions default to gray when they have no signal.
My bet is your issue is related to the set being on the wrong input or the source is net setup
Press the input button on the set and see what input you are on scan through them and see if you can find your signal also try inputing 03 on the remote and see if you get any change in the background.
Let me know,