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Hello! I changed silent button on iphone 6, then i put display back, turn on phone and start putting esd shield. I put 0,1mm longer screw in down left hole, i heard cracking and when i heard cracking i tako out screw. I put back screen and start testing phone. At one moment screen comming black and turn off completely. I connected phone to itunes, itunes recognized it, but screen is black. Its not backlight problem i saw. I put new display but same again. I force restart it, disconected battery and all that i found on the web. Any ideas?
Unfortunately, it sounds like you have Long-Screw Damage. If you want to be certain before sending your logic board out for repair, I would start by testing a bare-bones setup. Start by disconnecting the battery first (always!). Then disconnect the digitizer, LCD, front camera, rear camera and home button extension flex (see this guide). Now re-connect the battery; you should only have the battery and Lightning Dock flex connected. Connect a known-good, preferably Apple-original Lightning cable to an iTunes enabled computer. If you have access to a multimeter, you could measure the battery first. If it reads ~3.8V - 4.2V, then it is good. Does iTunes recognize your phone? If so, then you should re-connect one flex at a time until the phone stops working. I would start with the Home button flex first, then add the rear camera, LCD & Digitizer then from camera flex. If the bare-bones setup does not get recognized by iTunes, then you most likely have a logic board issue. You could send it (or find a local) to a repair shop that specializes in micro-soldering repair. Many shops offer mail-in service and offer a no fix / no fee policy.
