Thanks for merging it! Maybe it helps me, too… 
And, yes, I’ve “tried to dry” the FP2 several times yet.
But nobody knows the meaning of the screen (s. my photo!)?
It appeared again – by trying to reset the battery after inserting the USB cable. The screen keeps after disconnecting the cable.
Only result: the area above the battery gets hot. So I took it out of the phone.