The on a BlackBerry screen indicates that the device cannot detect a valid or functional battery . This usually prevents the phone from booting up, leaving it stuck on a black screen with the crossed-out battery icon. Common Causes
If the battery is completely dead, the phone may not stay on long enough to charge it. Try these cycles to "jumpstart" it:
: Dust or corrosion on the gold contact pins prevents the battery from communicating with the device.
: A non-original or incorrect battery model is inserted.