dtmf
I think Anne said that the phones that didn't ring would not ring even in the self test. During a self test the phone will do a bleep bleep ring at the end of the test.
Anne
It's hard for me to believe that 3 phones would all have the same problem of not ringing. I would re-program (like dtmf suggested) the 3 phones to ring again and make sure your not in Night Ring (turned off and on from station 10 or receptionist) and double check on the rear of the phones that the ringer is turned to on.

Hope that help's
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