[quote=pvj]The first thing I would do is make sure both lines are connected to the telephone system. Dial 701 and you will pick up line 1.702 will get you line 2 and so on.

STILL.... dial 702 703 704 705 706
MIGHT find dial tone there! Yes/No?

Also, Dial the Main number with TWO CELL PHONES, does one ring busy? or both ring.
You could take a screw driver or the metal tip of pencil, by eraser, and SHORT the punch downs for this supposed 2nd line,
AFTER you Dial that 2nd number.
Dial that 2nd number. If ringing, it would stop and click with the short.