Flashlight sometimes doesn't turn on. Seems like hardware.

So after some water damage (ocean actually) in a spring (battery was depleted and phone was off during accident and washed and soaked in isopropyl alcohol shortly afterward) flashlight developed nasty bug — it is not turning on sometimes.

There is no really a pattern to that – no battery level or temperature don't seem to play a role here. Button is depressed on overlay sheet but flashlight is just not working, same for camera flash when that happens. Sometimes it is ok.

If anyone can provide some inside how to troubleshoot it I'll be eternally grateful. Thank you