Phone won’t turn on, high pitched small hissing sound when charging
Hello. I have an iPhone 13 that I bought. It doesn’t turn on, it doesn’t get recognised by laptop and doesn’t show any indication when charging, but the only thing it does when plugged into a charger is that I can hear very quiet high pitched hissing sound from inside the phone. When I first plug in the charger the sound is very small and it can be heard in ticks ( silence “tick” silence “tick”) like it’s trying to block electricity and over time the sound changes patterns and can be heard constantly. I also learned from the person I took the phone from is that when plugged into a charger for a while the phone gets hot. Might be a component in the motherboard that is getting hot when charged for a long period of time and I don’t want to repeat that because it might destroy the phone more. I want to learn repairing phones so Iam looking for answers of how to start troubleshooting. I suspect the fault being from the motherboard. I want to know how to get to the problem rather than just knowing what the problem is, though I would appreciate if anyone knows what the sound indicates. My question is, where and how do I start troubleshooting the motherboard.
Thanks in advance
Hello again, sorry for the late reply. Took some time for the majority of the tools to arrive. I plugged my probes into the battery connector and it shows a fluctuation in the amp draw. This only shows when I plug the phone into a charger. I don’t need to press any buttons, it just starts to draw when plugged into the charger. What does this tell me and what do I move on into now?
Edit: here’s a video https://streamable.com/mrxpbu