RIM BlackBerry 7510 Troubleshooting
"Phone will not turn on at all after being charged"
The phone will most likely not turn on because the battery has died or worn out. Initially, charge the battery and restart phone. If charging your phone does not work then replace the battery entirely.
After checking the battery, test to see if the problem is from a fault logic board. If this problem occurs, you must replace the logic board.
"Broken or cracked screen."
Remove old LCD screen and replace with a new one. If problem persists, replace the device.
"Malfunctioning or Broken Antenna."
If you are not getting reception, remove the old antenna and replace it.
"Malfunctioning Vibrating Mechanism."
If your phone no longer vibrates when set on vibrating mode, then the vibrating mechanism needs to be replaced.
If none of the above solutions solve the problem with your Blackberry, replace the unit. Fortunately, it is an early model and is available for a very reasonable price.