Trouble shooting AOR series trouble lights

Troubleshooting AOR Series Trouble Lights

PURPOSE
The purpose of this document is to explain the various reasons for trouble status Lights on the AOR series Command Unit. This includes the AOR-8, AOR-16, AOR-24, and AOR-32. The AOR command units will test the circuit integrity from the main AOR system boards, through the open/short detection board, and out to the call stations.

To reset the trouble detection system, there is a reset button on the front of the command unit.  The first press of this button will silence the audible alarm for 24 hrs.   The second press of the button will retest.

Individual Station Trouble

Individual station trouble is indicated by a solid red LED in the trouble column on the front of the AOR Command Unit. One or more LED may be illuminated indicating an individual issues with that station or it's wiring. There are several issues that can cause the illumination of the LED. They are an open circuit, failing to detect a connected call station, and a short in the circuit.


  1. If a single or several station lights, but not all are illuminated.
    1. Is there currently a call station connected to the port in question?
      1. If yes, what model is the station?
        1. If ETP-110, can the station be reached from the local handset?
          1. If Yes, check the polarity of the ring and TIP connections to the open/short detection board. The ETP-110 stations are not polarity sensitive, but the error detection algorithm is.
          2. If no, is the station status light illuminated?
            1. Yes, the station is seen as off hook, and can not be reached. This may indicate a short in the line, or an issue with the call station. Disconnect the call station and see if the light Station Status light remains illuminated.
              1. Yes, this is a short in the wiring.
              2. No, this is an issue with the call station, try an alternate call station on this line.
            2. No, there is an issue with continuity to the call station, or the Call station has failed
              1.  Try an alternate call station on the line, be sure and press the reset button on the command unit twice after connecting to see if the trouble LED clears
                1. Yes, the trouble cleared, this is an issue with the station
                2. No, there is an issue with the continuity of the line to the call station.
        2. If ETP-500 series, Can the station be reached from the Local handset?
          1. If Yes, check the polarity of the ring and TIP connections to the open/short detection board. The ETP-500 stations are not polarity sensitive, but the error detection algorithm is.  Did this resolve the issue
            1. No, has the ETP-RES-KIT-2 been installed at the station, replacing the original connector for the Telephone line with the one that includes the resistor?
              1. If the ETP-RES-KIT-2 is not connected then the error detection algorithm does not believe the ETP-500 is connected.  The ETP-RES-KIT-2 is available at no cost.
          2. If no, is the station status light illuminated?
            1. Yes, the station is seen as off hook, and can not be reached. This may indicate a short in the line, or an issue with the call station. Disconnect the call station and see if the light Station Status light remains illuminated.
              1. Yes, this is a short in the wiring.
              2. No, this is an issue with the call station, try an alternate call station on this line.
            2. No, there is an issue with continuity to the call station, or the Call station has failed
              1.  Try an alternate call station on the line, be sure and press the reset button on the command unit twice after connecting to see if the trouble LED clears
                1. Yes, the trouble cleared, this is an issue with the station
                2. No, try reversing the polarity of the ring and tip connections and pressing the reset button twice.  Did the trouble light clear
                  1. No, there is an issue with the continuity of the line to the call station.
      2. If No, this would be the reason for the failure.
        1. Should a station be connect to this port?
          1. Yes, connect the station and press the reset button twice.
          2. No,  make sure all unused ports are at the end of the available ports, and adjust the dial near the station 1 terminal to the correct number of ports.

All Stations Trouble
All station trouble is when an entire bank of trouble LED are illuminated there are two issues that can cause all trouble LED be illuminated.
  1.   Is the power light for the bank illuminated?
    1. Yes
      1. Verify the ribbon cable that connects the Open/Short board to the main board for the bank is not disconnected from the open/short board.  This is the rainbow colored ribbon cable that connects to COMM pm the Open/Short board.
    2. No,  verify the barrel connector is connected to the main board for the respective bank.
  2. If neither of the above solutions correct the problem then each trouble light will need to be viewed as an individual issues specific to that port, cable, and call station.

Ground Fault

The Ground Fault error is system wide.  Any Trouble LED, that is not solid with an individual error will be flashing.  This is a difference in the ground potential between the Open/Short detection board, and the rest of the system.



  1.   Disconnecting the Green Ground wires from the three pin green power connector(J11) of the Open/Short board will provide a temporary remedy to this issue.
  2.  Connecting the ground wire(s) from the Open/Short board to the AC ground instead of the Chassis ground of the case may resolve this issue.
  3.  There may be voltage shorting to the case of the Command unit, or the conduits connected to the case.