MULTIPLE DISTRS AND COM PROBS DURING ARR TO LAS VEGAS; NV; ON THE LYNSY RNAV 1 ARR LED TO TRACK AND ALTDEVS CAUSING DEPS TO BE STOPPED FOR A SHORT PERIOD OF TIME.

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WHILE ON THE LYNSY 1 ARR INTO LAS; WE WERE CLRED TO CROSS LYNSY AT 12000 FT AND CLRED THE ARR. IN THE DSCNT; I CONTACTED LAS OPS. I HAD BEEN HAVING PROBS WITH MY CDU BOX SO WE HAD CHANGED THE PRIMARY RADIO TO VHF #2 BECAUSE I WAS HAVING PROBS WITH VHF #1. DURING THE TIME I WAS CALLINGS OPS ON VHF #1 (GETTING GATE INFO; AND TALKING TO MAINT ABOUT MY RADIO PROBS); I LOST RADIO CONTACT WITH OPS. I INITIALLY THOUGHT IT WAS MY RADIO SELECTOR PANEL ACTING UP AGAIN. AFTER TRYING THE RADIO SEVERAL TIMES; I REALIZED THE CAPT HAD STARTED USING VHF #1 AS PRIMARY. I REALIZED OUR MISTAKE AND SWAPPED BACK TO VHF #2 AS PRIMARY. DURING THIS RADIO GAGGLE; WE LOST CONTACT WITH APCH. THE CAPT CONTINUED ON THE APCH; DSNDING AS DEPICTED ON THE ARR. COMPANY CONTACTED US AND GAVE US APCH FREQ AND TOLD US THEY WERE TRYING TO GET A HOLD OF US. WE CONTACTED APCH AND NOTIFIED THEM OF OUR RADIO PROBS. NOTHING WAS MENTIONED UNTIL WE TALKED TO GND. GND TOLD US TO CONTACT ATC. THE CAPT TALKED WITH ATC AND THEY SAID WE WERE NOT CLRED OUT OF 12000 FT. THE CAPT AGAIN CALLED ATC WHEN WE GOT TO LAX. ATC CHKED THE TAPES AND REALIZED THE CAPT TWICE SAID HE WAS FLYING THE ARR FOR WHICH HE THOUGHT HE WAS CLRED. ATC SAID THEY WOULD NOT VIOLATE US BECAUSE THE CTLR MISSED THE CAPT'S READBACK. SUPPLEMENTAL INFO FROM ACN 566571: I FLEW THE LYNSY 1 AS DEPICTED; DSNDED AS I THOUGHT WE WERE CLRED. XING MIROK AT OR ABOVE 11000 FT AND UTARE AT 8000 FT. UPON LNDG; I WAS DIRECTED TO CONTACT LAS TWR BY PHONE WHERE I LEARNED FOR THE FIRST TIME OF THE ALTDEV. TAPES WERE CHKED AND TWICE I HAD TOLD CTLR THAT I WAS 'LYNSY 1 PROFILE DSCNT' -- ZLA MISSED MY IMPROPER READBACK AND DID NOT CORRECT ME TO DSND AND MAINTAIN 12000 FT AT LYNSY. DEPS AT LAS WERE MOMENTARILY STOPPED UNTIL THEY GOT ME BACK ON FREQ. HE SAID I WAS OFF FREQ FOR JUST OVER 5 MINS. BECAUSE OF THE RADIO PROBS MY FO WAS EXPERIENCING; AND HIS NEWNESS TO OUR OP; I WAS MONITORING BOTH RADIOS -- TRYING TO ASSIST HIM. I KNEW LAS WAS LNDG ON RWY 1L&R; BUT BECAUSE OF THE NOTE ON THE LYNSY 1; THAT ACFT ARE 'TO PROCEED VIA LNDG RWY 25L UNTIL OTHERWISE INSTRUCTED BY ATC;' I DID NOT QUESTION IN MY MIND; ROUTING AND ALTS ON THE ARR AND WAS EXPECTING THE PROFILE DSCNT WHICH LED TO MY ERROR. I DID NOT REALIZE THAT WE HAD LOST CONTACT WITH LAS APCH UNTIL I HAD ALREADY COMMITTED MY ERROR. IOE AND RADIO DIFFICULTIES WERE DEFINITELY CONTRIBUTORS.