Sony TV sleep mode

Hi,
I have a Sony KV2080R TV that keep getting stuck in "sleep mode". Does anyone have any idea how I might fix that? I've tried pressing the sleep mode button but that doesn't seem to do anything. When I power up the TV, I can hear the tube "click" on but there's no picture. The sleep mode LED/light is on/red but I can't get a picture. It's like it's in sleep mode and can't wake up.

Any ideas? Thanks, Joe