Hi there ... We have 4 lines in the office but on one of our M2000 series Meridian phones only the first 2 line buttons receive a dial tone ... How do add lines 3 and 4 to the next 2 buttons?

Programming is done on M7310, M7324 and T7316 sets.
To set up line appearence you need to enter programming by pressing the feature key followed by **266344.When prompted to enter the password enter 266344.
The screen should say TERMINALS&SETS. The 4 top line/feature keys are now used for programming.
At the terminals&sets prompt,
press the show key (top right arrow).
The display should now ask for an extension number. Enter extension number you wish to program the new lines on.
Press the show key (top right arrow)
The display should sat LINE ACCESS
Press the show key (top right arrow) .
The display should say LINE ASSIGNMENT.
Press the show key (top right arrow) .
The display ask for a line number. press list
The display should say line 001: appear & ring
press the next key (bottom right arrow) till it says 003:unaaign.
press the chng key till the screen says appear&ring
Press the next key(bottom right arrow)
The display should say line 004: unassign
press the chng key til the screen says appear&ring
press the Rls key when finished

We have M7310 phones, that used to have 3 lines working, now when you dial the line 3 #, you can only answer it from the intercom button. The line 3 buttin now seems to be programmed for last # redial.