Chosen Solution
My phone randomly shut off. I have tried many things, with no luck. I have replaced the screen, battery, charge port, and disconnected the back camera. Nothing will get the phone to boot. It shows no sign of life. Any other suggestions??
Definitely seems like an issue with the logic board. To get that fixed it would at least require some microsoldering work to get it working. You may be able to find someone locally in your area that does board level repairs on iPhones.
