My I pod nano's display not working

christo, unless you clean it, you are running risk of corrosion and further failure. I would suggest that you follow this guide about how to take it apart. After that I would suggest you check this wiki about what to do with the submersion. Clean it properly, change your battery and reevaluate for further, if any, damage. this model is a bit of a PITA to work on, but it can be done. Just read the guides, make sure you understand them, follow the exactly.The iPod Nano is a habitual trouble maker with the back light :-). I know that the 4th and 5th gen are some of the worst ones. Now the backlight is actual part of the LCD, you may have to replace that as well. The inverter circuit is on the logic board. I have never managed to isolate a coil etc. that is responsible for most failure on the Nanos. Hope this helps, good luck.