What was found
DURING CLIMBOUT SWITCHED WEATHER RADAR FROM STANDBY MODE TO SEARCH 3 MODE. RADAR SCREEN WAS FUZZY AND RT FAILURE LIGHT WAS ILLUMINATED. AT FIRST SUSPECTED MOISTURE AND WAS WAITING FOR MOISTURE TO EVAPORATE. AFTER APPROXIMATELY 15 SECONDS NOTICED ACRID ODOR FROM UNDER PANEL. IMMEDIATELY SWITCHED RADAR UNIT OFF TO SEE IF THAT WOULD CLEAR THE ODOR. ODOR MARKEDLY DECREASED. TURNED UNIT BACK ON AFTER APPROXIMATELY 1 MINUTE TO VERIFY RADAR UNIT WAS SOURCE OF ODOR, AFTER 5-10 SECONDS THE ODOR RETURNED. TURNED RADAR OFF AND RETURNED TO ORIGINAL DEPARTURE LOCATION. RADAR RT WAS REPLACED WITH SERVICEABLE UNIT AND AIRCRAFT RETURNED TO SERVICE AFTER SUCCESSFUL OPS CHECK OF RADAR SYSTEM.