When i turn on the tv, it makes the start up noise and i can hear the sound, but there is no picture and the LAMP light flashes. After about a minute the tv turns off and back on and the light continues flashing, then it turns off and 3 lights begin to flash, when i hit the power button it turns on but still no picture. This has happened multiple times before and it fixed itself in a matter of minutes. This one has been doing this for about 18 hours, what should i do?