does not sound good, but... you might try simply putting the power supply in direct hot sun for a day. Thinking of when I had a cell phone get dunked... that often works. Be sure to put any vent holes or case seams "up" so any water can evaporate fully. That should get it thoroughly dry. Since we don't know what's inside as far as electronics, that's all I can come up with. You might just be lucky on this one. Be sure to reset the GFCI before you plug it all back in. Also, check to see if there is a built in GFCI on the power supply, too, and reset if present. Good luck!