What was found
DURING CRUISE STARTED SMELLING ELECTRIC BURN SMELL AFTER ABOUT 20 MINS WE HEARD THE AVIONICS FAN GRINDING AND COMING TO A STOP FOLLOWED BY THE AVIONICS COOL FAN CAUTION MESSAGE BEING DISPLAYED. FOLLOWED THE NON-NORMAL CHECKLIST, MESSAGE WENT AWAY. IT APPEARED AGAIN ON THE GROUND IN SLC. PERFORMED MAINT AS REQUIRED & DEFERRED NR 1 DISPLAY COOLING FAN IAW MEL 21-24-2C. ENTERED INTO MM02. MXC 1390 NOTIFIED. PULLED AND COLLARED C/B U2-- REMOVED AND REPLACED NR 1 DISPLAY SUPPLY FAN B12 P/N AE0804A04, S/N OFF 01185, S/N ON 01048 IAW AMM 21-24-12. CLEARED FROM MM02, MXC NOTIFIED 0782.