I managed to spend about ten minutes in (fresh) water with my nexus 5 in my pocket recently.
I took it apart, dried it off and charged it.
I can get the phone to boot but only ever see the faint glow of the backlight at the bottom of the screen. The display, and it seems the touch functionality, are not working. I know the phone boots because it rings when I call it, I hear notifications and I was able to connect to it via my PC and copy across some data. When I press the power button the backlight comes on but only after a few presses whereas I would expect it to kick in immediately.
I decided to buy some isopropyl, removed the pcb shields and soaked and scrubbed the boards.
This made no difference, still all I see is the backlight.
I thought the lcd was broken so ordered a replacement but it turned up today and it shows the exact same behaviour, backlight only.
Any ideas how I should proceed to troubleshoot this. Apart form the power switch which doesn't seem to be responding as I would expect the phone motherboard must be (almost) fully functional as it connects to the network and receives calls, texts and emails.
Thanks for any advice you can give!
I should also add that I disassembled the screen and cleaned the diffuser, lenses, etc. with isopropyl.
Before doing this when looking at the right angle with the backlight on I could make out water trapped in the screen.
It's now all clear but still didn't fix the lack of pixels