Chosen Solution
I’m trying to pin-point a suspected short-circuit that is causing heat to be focused on the main speaker during standby. There are several unrelated issues with the phone: touch ID not working, mute switch not working, and non-OEM battery. I guess any of these, or indeed the speaker itself might be the source of the issue. My plan is to open up the phone and eliminate each of the suspect components one at a time by removing one of the connectors and re-booting whilst suspect component remains disconnected to check for reoccurrence of the short. Will this work (i.e. will the phone start-up without all components being plugged in) and is it safe for the phone for me to do so? Thanks.
Absolutely, that is the proper way to troubleshoot a suspected faulty modular component. Always insure to disconnect the battery before disconnecting or reconnecting a module though. Ultimately, you can boot the phone with just the battery and Lightning port connected to an iTunes enabled computer. iTunes will recognize it and you can also use a tool like 3uTools to access data, flash the iOS etc. as long as the device is not PIN locked or untrusted on that computer. Make sure you trust it before and remove the PIN and then start troubleshooting :>)!
