iPod nano 3rd gen not turning on

I got this as a gift on the Christmas of 2007, July 2011 apple juice had spilled in my bag with the ipod in it. I quickly dried it off but as I was an hour away from home, I couldn't just put it in rice.

I got home and it still worked but gradually weird stuff started to happen. Almost 6 years later, I found it again, turned it on, the screen was still dark but it looked like there was some light beneath the darkness ( I can't explain it better than that). Basically when I turned it on, something happened but then it just went back to normal.

So is there any way to salvage what's left of this iPod, even if i took it to get it fixed, would there be any hope ? Out of curiousity, when an iPod or anything like it gets water damaged, what do they replace to fix it ? For example do they just change the battery ?

Thanks