What was found
(CAN) ACFT RETURNED TO GATE DUE TO LOUD FEEDBACK ON CAPT`S AUDIO AND REPORTED ELECTRICAL SMELL. MX CONFIRMED CAPT`S ASP FAILED/SMOKED UP. DEFECT G69984 CREATED 10/09/2011 READS NR 1 RADIO FAILED ON STARTUP, HOT ELECTRICAL SMELL IN COCKPIT. THE DEFECT WAS RESOLVED THE SAME DAY, RESOLUTION READS NR 1 RADIO AUDIO SELECTOR PANEL, PN 5145-1-77, SN 12152 WITH A TSI OF 10012, WAS REPLACED AND TESTED IAW AMM 23-50-00. REPLACED UNIT IS PRESENTLY ON RO 203322. SDR WILL BE UPDATED WITH TEARDOWN INFORMATION ONCE AVAILABLE.