I have a water damaged Nexus 5x. It was soaked in the beach for about 1 minute before it was taken out... the phone was only opened for drying after about 4 hours.
The phone's OS was corrupted and it will not power up unless the phone was connected to the charger.
So to try and save the phone, I bought a $15 battery replacement.
I have since rebuilt the phone's OS and it is now running. But the problem now is that the phone keeps turning off unexpectedly. For example, the battery indicator may say 97% but after a few seconds or minutes, the phone will turn off anyway. I tested the battery after removing it and the voltage reading was about 4.3 v so there is enough charge in there to actually fire up the phone.
So I was hoping that it was the battery since the battery seemed like a chinese knock-off. So I opted for a local supplier who advertised that he is selling a genuine $30 battery replacement. After installing this battery replacement, the phone worked again for a few days without any issues. Unfortunately, this time, the phone stopped working and the battery doesn't seem to want to charge at all. Even when the phone remained connected to the charger, the phone still won't start up. I removed the battery and the voltage reading was 3.6 v
So I re-installed the first replacement battery I had. And the phone is now powering up again. But it has to be connected to the charger for it to keep working.
In addition, the button for the 'volume increase' is also not working... but the 'volume decrease' and 'power' button works fine.
I have tried to clean any gunk and corrosion that built up due to the water damage and the motherboard appears to be clean. What do you think is wrong with this phone?