Mine did that when I first tested it out, but for some reason I can't explain, it just started working a minute later. Haven't got a clue why. I'd try putting a known good hard drive in to hear out via the clicking whether it's actually booting or not. Make sure it's running the right system version. That would narrow out some major logic board issue and confine the problem to the LCD itself or something in the display circuit (such as the inductors). How bad did the original caps leak?