How do I Use a T1 Loopback Connector to Test a Starlink SL9003T1?

1. Unplug the T1 line. Plug the T1 loopback connector into the T1 port on the MUX card. Watch for all of the MUX, Encoder and Decoder LEDs to change to a steady GREEN color, except for the one orange LED on the T1 port. If the Moseley T1 chassis contains only one Decoder card, the LED on the Decoder card will flash GREEN. 
2. If the Moseley unit has an Encoder and Decoder card, apply an audio signal to the Encoder card and then monitor the output from the Decoder card.
3. If the Moseley SL9003T1 operates normally, talking to itself in loopback mode, the problem is most likely the T1 line.