I do not think the card can auto sense the type of cable on it. You can build a T-1 loopback cable. The pin-out is 1,2,4,5. Tie pin 1 to pin 4 and pin 2 to pin 5. This will loop the signal back to the carrier. An even easier way to do it is to have the T-1 WIC card provide the loopback facing the line. Then call your carrier to verify if they still see a yellow alarm. Do you see alarms on your CSU (SHOW CONTROLLER T1)?? IF he is seeing a yellow from you then you are probably seeing a RED alarm from him. I would verify that you have the correct framing and coding on the line. I know you said that the old line works fine, however you may have differing framing and or coding on the new line. The SHOW CONTROLLER T1 command should show you whats happening....