Diy Samsung Galaxy s23 ultra FPC connector replacement
Hello everyone, I'm kind of new to this. I have a Samsung Galaxy s23 ultra (1tb model, soo buying a new phone for over 1000$ isn't currently an option) that recently went swimming and since then I had some issues where it would reboot at random times. As time went on, it was happening during the charging and when battery percentage was above 50%.
I then replaced the battery and the USB port board and the issue went away for day, but came right back but this time it's when charging and the battery above 40% as well as when battery is above 70%. I also noticed when I'm actively using the phone the reebots are less common and pretty much only happen during charging when the battery is at higher percentages.
I then decided to take the phone apart and check the contacts. I found the FPC connector on the main board that connects to the batter looks a little sad. Some of the gold plating is gone and part of the plastic appears to be melted (maybe?). All other connectors on the boards and ribbon cables are fully gold plated. I did some looking online and saw that some of these connectors sold fully gold plated and some aren't.
I'm assuming gold plating is more important in this case as it's an inert metal that protects from mostly corrosion.
My current theory is that some small amount of moisture got in and started a micro rusty spot on one of the pins, so that when battery reaches higher voltages there's a short and phone shuts down and reboots or that the jumping spark along with increased temperature from charging causes momentarily overheating and phone reboots.
I have pictures of those connectors, so I attached a collage to the post where the issues connector is in 2 bigger pictures on the left. If anyone had any advice on what the issue is or how can I solve it, it'd be much appreciated.