Jackie
I would recommend the following:
- Log on to the phone system and go to the F screen.
- Install the second station card and do not plug in the Amphenol connector.
Does the system recognize the station card?
Can you program the extension in the F screen?
- If yes, disconnect all phones (unplug from the base of the phone) and reconnect the Amphenol connector to the station card.
Does the system still recognize the station card?
- If yes, plug in one phone and check the F screen for the correct programming.
Follow this procedure for each phone.

If the phones system runs with one station card installed and fails when the second card is installed, problem may be with the system power supply. (I’m assuming the second station card tested ok)

Good luck
Walt