Problem??

I finished charging a pack, display readout was as normal expectations information of charge. , When I removed the pack plug the display went blank, then blinked four square blocks and a couple dash lines and thats it.

Strange enough, so I disconnect power lead and it does same thing on boot up. Nothing but squae blocks followed by dash lines.

Any clues??

Nothing inside looks or smells fried, I know the typical return route but was hoping for more help this side of pond .