I gutted my 3G iPhone 8GB last night to install a new candy apple red back housing. When I purchase the iPhone a couple weeks ago, it had a broken home button and cracked back housing, so I thought this would give me a chance to escape my Macbook repairs and branch into iPhone repairs, too. So, I purchased a new home button and back cover from eBay. I then followed iFixit tear down instruction to remove all components from back cover, and then reinstalled them in reverse order into the new back cover. I then proceeded to tear apart the screen assembly to install the home button. Despite the home button be a little crooked, and that it doesn't really click properly, everything went back together okay. Then after I attempted to reinstall the LCD assembly, the iPhone would not display anything. However, the vibrate button activates the vibration mechanism (with and without LCD assembly attached), so I know logic board is functional (or do I?) Also, when the LCD assembly was off, I removed the logic board connecter and reinstalled that repeatedly. When I did that, the vibration mechanism momentarily sounded. Also, I did tinker with the on-off button and home button combo after assembly. Nothing turned on, though. A friend suggested a new LCD. So, I figured I'd try swap it out with my wife's iPhone 3G 8GB assembly (nobody tell, please!!). Then after taking the LCD assembly off, installing another one still nothing displayed. Thankfully, when reinstalling my wife's LCD her LCD displayed as original. So at this point is what I know: 1) The iPhone was fully operational before disassembly (minus home button) 2) The vibration switch activates 3) The vibration switch activates when removing/reattaching motherboard connecter (the silver attachment). 4) I got a cool looking back housing, but no iPhone yet!! LOL! 5) The LCD assembly is good, as I tested it in another iPhone 3G 8B. Questions I have a this point: 1) Is this a software or hardware related issue? 2) Is there a ground somewhere in the back cover assembly that failed to touch/connect when installing new back cover? 3) Is there some sort of reset I need to do after disconnecting motherboard? 4) Do I have to follow the numbers when dislocating/reattaching connectors? Any assistance would be helpful! Thanks!