84 & 87 are only needed if you put the system in day2 or night mode. Most people don't use it except for different after-hours ringing, night bell, or immediate VM answer.
In prog. 81, set int, L1, L2, & L3 on (line 1 uses int. button) and the rest off for 201, 202, 203, & 206. Set L4-L7 on and the rest off for 204, 205, 207, 212, & 213, also L8 for 213. If the light is on it rings, if off it doesn't ring. Prog 82 & 83 are used for delayed ringing.
Is the door physically connected to a CO port or is it just a programmable button at line 9 position?
When you said the extensions are not ringing, are the buttons red or green? If they're green, it could be a bad phone.
