As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#278, LAS-BOS. (ETOPS) 'WITH THE WXR/PWS SWITCH IN POSITION #1, THE CAPT'S ND DISPLAYS A RED WXR R/T MESSAGE, INDICATING TRANSCEIVER FAILURE; PFR READ RTU 1. SWAPPED RTU WITH RTU 2. PROBLEM FOLLOWED. REMOVED AND REPLACED RTU 1 IAW AMM 34-41-51. OPS CHECK GOOD. RTU 2 WAS REINSTALLED IN ORIGINAL POSITION. WXR1 AND WXR 2 PASSED OPS CHECK IAW AMM 34-41-00. A/C OK FOR SVC.'