Why is there a red cross on screen?

Please try this sequence, it will take 4h15m your BB must remain connected to a known-good wall charger (not PC USB):

With the battery inside, connect your BB to the wall charger

Leave it alone for 2 hours, no matter what the LED or the display does

Remove the battery

Wait 15 minutes

Insert the battery

Wait another 2 hours, no matter what the LED or the display does

This has been known to "kick start" some BBs.

Hope it helps.