Chosen Solution
TL;DR : My phone broke after a restore, won’t turn on or connect to my computer, heard about iOS 5.1.1 affecting parts. I did a restore to an earlier operating system (iOS 5.1.1) today on my iPhone 4 and it didn’t show anything on the screen at first. I took off the back and reseated the battery and the display connector and it seemed to work. I then plugged it in and the screen went black and the phone went into DFU mode. I restarted the device and it didn’t turn on after the restart was complete (after the apple logo displayed). I disassembled it again and now it doesn’t seem to turn on or recognise it in iTunes or the Linux virtual machine I have on my Mac. It is either the cable or the internals inside the the iPhone itself. I have heard rumours that it is a problem with iOS 5.1.1 (having a counterfeit screen and nothing will work) and that the only way it will work is if I replace the screen and it will now work. Only it has had no new screens on it and I can’t go into iTunes and restore it as it now won’t work with iTunes even though I synced it with iTunes prior to the incident. I have tried hard reset and I have tried switching the volume switch on the side. The question is: How do I get it to boot up? How do I start up the phone and get it working?
If the phones already gone into dfu mode, likely you’ve lost whatever you haven’t backed up. I would assemble the phone, or at least the display logic board and lightning dock, then try to connect it to iTunes. Then, if this doesn’t take, I would fully assemble the phone, then put it into dfu mode iPhone 4 Teardown You may want to use this guide, to check your connections. I’m starting to wonder if it’s one of the connectors, near the LCD/digitizer, that’s either not connected properly, or has been damaged
