WDB ON APCH HAS LOST COM.

Narrative

WHILE BEING VECTORED FOR VISUAL APCH TO EWR; WE LOST COM WITH ATC. WE THOUGHT WE HAD A STUCK MIKE SO WE TRIED UNPLUGGING ALL MIKES AND TRYING TO ISOLATE THE PROB. WE SQUAWKED 7600 AND TRIED THE #2 RADIO; BUT BY THEN APCH HAD CHANGED ALL OTHER ACFT TO ANOTHER FREQ; SO WE COULDN'T GET AN ANSWER ON #2 EITHER. BY NOW I ELECTED TO CONTINUE FLYING OVER THE USUAL RTE FLOWN WHEN LNDG TO THE S AT EWR; FOLLOWING AN ACFT AHEAD THAT WE SAW VISUALLY AND ON TCASII. I FLEW WHILE THE FO AND SO TRIED TO ESTABLISH COM. PRIOR TO LNDG; WE WERE ABLE TO CONTACT THE TWR AND RECEIVE LNDG CLRNC. THE ONLY STUCK MIKE PROBS I'VE HAD INVOLVED AN INDIVIDUAL MIKE. I THINK THIS LED US TO AT FIRST CONCENTRATE ON FINDING THE BAD MIKE; RATHER THAN CHANGING RADIOS. WHEN WE DID CHANGE RADIOS; THE LACK OF AN ANSWER FROM ATC MADE ME THINK THE RADIOS WERE STILL BAD; NOT REALIZING THAT ATC HAD SHUT DOWN THAT FREQ (BECAUSE OF US). SUPPLEMENTAL INFO FROM ACN 270771: ONCE WE MADE CONTACT WITH THE FINAL CTLR WHO SENT US TO ANOTHER FREQ; IT WOULD HAVE BEEN NICE TO EITHER STOP WITH HIM OR TO HAVE BEEN SENT TO A GOOD FREQ BECAUSE WE INITIALLY THOUGHT WE SOLVED THE PROB AND NOW WERE HAVING TROUBLE CONTACTING ANYONE AGAIN. SO WE HAD TO START THE CIRCUS ALL OVER AGAIN; IS ONE OF OUR MIKES; ONE OF OUR OXYGEN MASKS; RADIO INTERMITTENT; BAD FREQ; WHO WAS ABLE TO TALK WHAT RADIO WHICH SIDE; ETC. ALL THIS DURING THE LAST 8 MINS OF FLT.