Hi maybe anybody knows something not right with my tv, suddenly my tv does this in recent weeks, when I turn it on, it will turn it on and off itself, I forge the model number, this is the silver one and I have had this for 5 years, never had any problem before, I watch tv probably only 3-4 hours in weekdays and 4-6 hours in the weekend, I could hear the sound but no picture, sometimes it works when it urn it on and off several times.

Post full model number.
If this is a DLP, you probably just need to replace the lamp (five years is a long time on a lamp). There's a trap door on the side, pull out the lamp and inspect.