We live on a boat and Caden's WiiU and gamepad got wet during a nasty squall in St Augustine. Both the WiiU power brick and gamepad were non functioning afterwards. We bought a new power brick which brought the WiiU back to life, but the gamepad was still down on it's luck. The screen kept scrolling to the right, and a lot of the buttons wouldn't work.
Caden was able to follow the repair guides and easily disassemble the gamepad. I instructed him on how to clean the contacts with isopropyl alcohol. Caden did a lot of troubleshooting to make sure everything on his gamepad was working by repeatedly having to disassemble, clean contacts, re-assemble and test. A few times he would miss a step and not assemble the gamepad correctly, such as not connecting a cable forcing him to check over his work. Eventually he cleaned and assembled everything to where it was working again. The only function not salvageable by cleaning was the ZR button on the gamepad, which we ultimately had to order a replacement flex cable.
The repair guides were put together very well and Caden was able to follow the instructions easily. The only advice I gave him was on cleaning the contacts and to be extra careful when inserting the flat ribbon cables into their connections. I tried to stay out of his way and let him make mistakes on his own. He's very proud of himself for being able to fix his WiiU and get back to playing his new favorite game Zelda: Breath of the Wild. It was a great self confidence booster! Bonus picture of the working gamepad+cat!