As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(LOG 9047688) JUST PRIOR TO STARTING APPROACH AT APPROXIMATLY 5200' MSL THE FO AND I SMELLED A ACRID SMELL LIKE ELECTRICAL SMELL. THE #2 COM RADIO WOULD NOT ALLOW ANY FREQUENCY CHANGES VIA THE KNOB. R/R #R/R #2 VHF TRANSCEIVER AND #2 VHF RTP PER B737 AMM 23-12. MULTIPLE CREWS REPORTED ACRID SMELL AT SAME WAYPOINT (TUBED) SAME ALTITUDE DUE TO VOLCANIC ACTIVITY IN THE AREA.