There are several possible reasons for why the radio is not responding:
- Power is down and the backup battery is drained. Hold the 6 key for 10 seconds to verify the voltage. If it is less than 6.2 Volts then you need to make sure the battery is connected and let it charge for 24 hours.
- Verify the connections on the AC Transformer (it should be connected to terminals 4 and 5, underneath the battery in the panel) and make sure it is plugged into the wall.
- Wireless signal strength issue or coverage issue - Press and hold the 5 key for 10 seconds to verify signal strength. See this video for more help.
- The radio may need to be power cycled. Please refer to this link for information on how to open the panel and remove the GSM. Once you have removed it, reinstall it the same way that you would add a new GSM and power the panel back up. Then wait 10 minutes and press "Status" followed immediately by "Disarm" to clear out the old error message.
- The radio has been tampered with, destroyed, disconnected or has otherwise malfunctioned. Check the LEDS on the unit.
- Lastly, make sure the antenna is connected to the radio. Unscrew the antenna and reconnect it to the panel. Make sure that the antenna is going in smoothly and is not cross-threaded.