screen go's off it show a picture of battery with X?
what happens wen the screen go off and it show a picture of a battery with a red X? And will not power on!
I've never seen anything so poorly documented. The red X on the charge/battery symbol usually means that there is no battery installed. Remove the battery and clean the gold connectors on it with a dry soft cloth. Put it back in afterwards. If it still won't register, you may need a new battery.
I just bought a used blackberry 9780 with this problem; I found it was caused by the battery not having sufficient connectivity to the blackberry. It worked when I pushed and held the battery upwards against the phone's connectors. My response is a bit dated here but anyone finding this answer might want to try this and if it's the case, find some way to keep the battery more firmly against the connectors.
The best way to try and fix this is take a pencil eraser and rub the gold connectors on the battery then wipe off the shaving that came off the eraser that are on the battery. I do this will all my old phones if the battery has troube it works perfeclty after that should give it a try. Sorry for such a dated answer I thought it would help if you still have that blackberry