first aid on the blackberry when suddenly blank(Blackberry blank solutions)

First aid on the Blackberry will be undertaken when BB was suddenly blank . email does not go-go . YM(yahoo messenger) can not connect . signals only GSM / GPRS only.1. Disconnect the battery at least 1-2 minutes.This function is the same as doing location update in common mobile phone, that if the type can only turn of / turn on again.2. Registration HRTfrom the Options - Advanced Options - Host