Camera will not power on.

After removing the back cover of my Panasonic GF3 so that I could repair one of the back panel buttons my camera will no longer come on. Originally after I put it back together I was unable to get the screen to work so I took the back off again to check the ribbon cables and after I put it back together the second time it would not come on at all. Any suggestions about how I could fix this are appreciated.

I have tried multiple batteries that are fully charged with no luck.