As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER RUNUP, HAD TO CONTACT GROUND CONTROL 2 TIMES FOR REPLY ON NR1 COMM. AFTER TAKEOFF CONTACTED DEPARTURE FREQUENCY 132.75 TWICE FOR REPLY AFTER SWITCHING TO 128.45, NEVER RECEIVED REPLY FORM CENTER. TRIED HEADSET/HANDSET AND SWITCH TO COMM 2 WITH NO ISSUES ON NR 2, RETURNED TO DEPARTURE. THE NR 1 COMMUNICATION RADIO UNIT WAS REMOVED AND ANOTHER UNIT WAS INSTALLED. UNIT WAS OPS CHECKED BY REPAIR STATION.