Mitsubishi VS-60703 Blue screen no audio or OSD

[alltronix]

Does anyone have any idea what might cause this problem? When first turned on after being off for several hours, set shows channel number for about 2-3 seconds then goes to blue screen with no audio or OSD. The filiments are lit on all three tubes, there is no response to any controls except power. No menu, volume bar or channel indicator. Any sugestions? Thanks