Chosen Solution
Hey, I had to replace the volume flex cable, after that I check my phone if it works and connected the battery and powered it on. Works, good. Then I disconnected the battery to put the screws for the screen protection plate (the thing that protects the screen connectors on the logic board), reconnected the battery an now it doesn’t show anything. I connected the phone to my computer and iTunes says it found a phone in recovery mode and I have to restore it to use it with iTunes. If I try to restore it im getting the 4014 error. I tried to check the battery with a LED and the LED lighted up so I dunno what happened to my phone. I also ordered a new battery but it will take 4 days . may someone could help me what i could do in the mine while, what i could check or something. Sorry for the bad English .
Try rebooting the phone by holding power and home. After doing this, does anything show up? The recovery symbol or a red or blue screen?
Are all 5 screws that hold the metal plate over the connectors from LCD to board/pcb in the right position? disconnect battery, remove all screws and the plate..hold down power button for about 10-15 sec. disconnect an reseat the lcd flex cables and connect battery..try to power on without screws and plate..even try rebbot as Josh W said..
