Picture has gone blank
Press menue to see if the menue pops up (yanno for sleep timer and stuff). If not, you need to have it repaired or need a new tv. You could try unplugging it from power for a bit, might help.
If you can see the menues then and your using HDMI, switch to a regular cable line and see if it comes in. Or just tune to channel 4 or somthing and you should get snow. Could just be the HDMI cable.
But if you cant get ANYTHING not even the Ch3 or Volume to show up on the screen, its the screen, a fuse or somthing else