Screen won't power on
Hi all, hoping for some suggestions. Bought a non-working iPhone 6, got it home put it on known-good battery & dock connector, drawing 900mA on my USB ammeter but wouldn't come on. Connected to iTunes, was able to do a complete DFU restore including installation of iOS 11 and went right through no problems. However at no time did the screen display anything and also I felt heat around the screen ribbon connector area, so once I got it restored and after checking with a flashlight to be sure that it wasn't just no backlight I took out the board and had a good look around under the microscope. I noticed straight away that a filter FL2024 was missing so tinned the pads, took one off a donor board and replaced it thinking perhaps that somebody knocked it off when replacing a screen. All seemed to go well with no problems, looks good under the microscope. However now when I put the board back in a known-good housing & battery the screen still doesn't come on but the phone's amp draw is fluctuating all over the place (but never gets above 500mA) when it had been steady before at a typical boot current. On the positive side the heat appears to have gone but that's not much consolation! One last thing; when I first opened it to have a look there were only 2 screws in the metal shield covering the screen connectors and the middle one which should have the smallest size of screw in it had a slightly larger one (not the really big one in the corner but too big anyway). I haven't done a lot of voltage testing on it yet (it's 1am here!) tho I will tomorrow, but would be really grateful for any hints or suggestions as to what might be wrong here.