Chosen Solution
new Hero 4 black submerged in salt water for 7 minutes. After thoroughly rinsing with distilled water then drying the camera, I let it rest in rice for 5 days. Now it won’t power up, make noise, or` give any indication of life left.
I had a GoPro Hero 4 Black sit at the bottom of the ocean for three days in a leaking waterproof case until a diver friend retrieved it for me. Amazingly, I was able to get it to power on. But I did the following first: Dismantled the GoPro immediately and washed all components in isopropyl alcohol.Ensure that all traces of corrosion (white) were washed off and that all metal contacts were cleanLet the components dry for several days Now the GoPro didn’t work 100% and required some parts to be replaced. What worked: WiFiHDMI outputLens & sensorPower and WiFi/Setup buttons What didn’t work: Some of the LEDsThe LCD displayThe shutter buttonThe SD card expansion slotThe battery (it swelled and oozed) Considering that your GoPro was only submerged for 7 minutes, chances are that yours is in better condition than mine was and so you may be able to salvage much of it and even possibly repair it to fully working order.
