Hi Bart,
Unfortunately, your description does not reveal what you "took a look at" in particular...
It could be that in the moment you saw the battery symbol on the screen, one of the connectors of the screen assembly was getting loose. Just open the iPod again and check it out.
You also mentioned that the volume button doesn't work any more. Has this been the case before you opened the iPod? I am not sure if the white screen is related to that issue. In any case, I would recommend to replace this cable, called power-volume flex cable.
I hope that helps.
Steffen