What was found
WHILE IN CRUISE AT FL 340 HEARD A THUMPING NOISE FROM THE RADOME OR AVIONICS COMP AREA. ALMOST IMMEDIATELY STARTED DETECTING A BURNING ODOR. COMPLIED WITH THE PHASE ONES AND QRH AND DIVERTED. UPON ENTERING COCKPIT NOTICED NO VISIBLE SMOKE, FOUND AVIONICS RACK FAN 3 CB POPPED. FOUND NR 3 AVIONICS FAN C/B POPPED UPON ENTERING COCKPIT. NO PAST HISTORY. REMOVED COVER TO INSPECT WIRING AT FAN AREA, NO DISCREPANCIES NOTED. OK FOR FLIGHT. MOCC NOTIFIED. TRANS ITEM TO MEL. R & R NR 3 AVIONICS COOLING FAN PER AMM 21-26-02-4 OPS CHECK GOOD, CIRCUIT BREAKER REMAINS CLOSED.