Chosen Solution
I have an iPhone 6s and the proximity sensor was not working and the touchscreen was unresponsive during calls. So I replaced the sensor assembly and tested the proximity sensor and it worked, but after a few minutes, the phone shut off and the phone above the SIM card got very hot. I unplugged the display/sensor assembly and battery. Now, whenever I plug in the battery connector, the logic board (above the SIM card) gets hot instantly. The phone does not turn on either. I believe logic board is shorted, but I’m not sure how this happened after successfully replacing the sensor assembly. Thoughts on what’s wrong and how to repair it? Thanks! Update (08/30/2018) Any insight would be greatly appreciated!
@refectio
It’s possible that the replacement flex was defective. Or perhaps the damaged was largely there beforehand and the rest is all coincidental. At this point, it seems pretty certain that you have a logic board issue so you will need to have this looked at by a tech that does micro-soldering repairs. If you have access to another device, you could either try the known-good flex in your phone or try the questionable flex in the known-good phone. That would tell you for certain where the issue is (although it’s not without risk).
