Phone doesn't switch on..

[Pondstrider]

I've had my eclipse Android "2.2" Smartphone about two months now I'm having difficulty switching it "on." It will ocassionally come on but the only sure way that seems to work is to plug the charger in..." then it lights up and I can "unlock." I take the charger plug out again and it works "fine..." that is,
till I turn it off again! Am I missing something OR is it just a dicky switch?