Chosen Solution
Yesterday, I changed the display/digitizer unit because the original screen showed a grey vertical bar on the left display side. I worked accoring ifixit repair guide. After reassembling, the display stays black, only the background lighting comes up. Beside this defect, the phone seems to work properly - it is recognized by itunes and i can flash/synchronize. What I tried: -I tried to reset (home+power) for several times -I tried to reinstall firmware (6.2.1) -I disconnected all non relevant connectors for testing basic function (i only left power button, display and battery) -I reconnected the old display unit But nothing helped. Did I brick my iphone or does anyone have a hint, how to get the display working again? Many thanks in advance!
You may want to check the miscellanious chips located around the sides of the connector for the LCD/Digitizer assembly. There is a chance that you could have damaged one while lifting up the connector from the old display.
Either a damaged chip as stated above or try isopropyl alcohol to clean the connectors as it might have a little water damage
