Sharp LC-32GD8E switches off after 5 secs

[IBuc]

Tv switches on then goes off after 5 secs.Have changed power board, Will stay on if holding the on button in , but once released goes off. any ideas.I have also changed the switch card to no avail.

 

[Titillating]

I don't know much about TV's, but to me it sounds like the problem might be related to your power button.