got a blackberry that all of a sudden died on me, it wont boot up but it does display a battery logo with a cross through it.

Blackberry desktop manager recognises it but i try to reload the blackberry OS back onto the phone but it wont reconnect to JVM.

Ive tried to connect the phone to BBSAK to wipe the device but it wont recognise the phone.

Can anybody give me a bit of help on this possibly thedr?

Also have another BB8520 and the trackball is really intermittent it selects when it is pushed down but it wont scroll.

Any help would be really appreciated!!