# RTU is dead: no lights or voice

If the RTU will not respond to the Power ON/OFF key:

Note: Refer to section RTU Interior View Diagram within the Installation Guide

1. Verify that the battery is connected.
2. Verify that there is primary power to the RTU. Verify that the yellow LED marked D33 on the main circuit board is illuminated. On the RTU Interior View Diagram, find the call-out labeled "Primary Power Present."
3. Verify that the power fuse, if any, is not blown.
4. If the RTU is powered via a plug-in voltage converter module, verify that the green LED on the module is lit. This would verify that voltage is being delivered to the output connector of the voltage converter module. Regardless of the input power configuration, if 12 VDC nominal power is reaching the main circuit board, the yellow LED marked DC INPUT on the main circuit board (located near the power input area) will be lit. If the power regulator circuit is "turned on", then the adjacent red LED will also be lit, indicating that even though the RTU seems dead, the product is turned on as far as the power supply circuit is concerned. (Do not confuse this single red LED with the array of six red serial port LED's.)
5. Verify that the front panel ribbon cable is properly seated on both the main circuit board and the front panel circuit board. Refer to the Interior View Diagram for a detailed view of the proper orientation of the front panel circuit board. This cable when properly plugged onto the front panel circuit board has the index color stripe arriving at the front panel circuit board with the index color stripe on the right hand side when the door is open.