First checks
Treat emergencies separately
This is a routine troubleshooting guide. In an emergency, follow your device’s emergency procedure and use any available emergency communications. Never trigger SOS merely to test a device.
Identify power and activation status
Record the model, charge indication and account status. Use the manufacturer’s guide for charging and activation, since requirements differ between devices.
Use the ordinary test procedure
Select your exact model below for pairing and any manufacturer-provided non-emergency test. Complete routine checks before travel, rather than depending on an untested device.