What was found
AHS 2 C/B POPPED WHILE PREPARING FOR NEXT FLIGHT, A RESET WAS ATTEMPTED AND CB POPPED WITHIN 1 SECOND THE CREW NOTICED AN ELECTRICAL ODOR COMING FROM THE CB PANEL AND FROM AIR VENTS IN GALLEY AREA THE ACFT WAS SHUTDOWN COMPLETELY AND THE ODOR DISSIPATED. H2 C/B POPPED WHILE PREPARING FOR NEXT FLIGHT A RESET WAS ATTEMPTED AND CB POPPED WITHIN 1 SECOND THE CREW NOTICED AN ELECTRICAL ODOR COMING FROM THE CB PANEL AND FROM AIR VENTS IN GALLEY AREA THE ACFT WAS SHUTDOWN COMPLETELY AND THE ODOR DISSIPATED. GAIN ACCESS, TROUBLESHOT, VERIFIED SQUAWK, ACCESS NR2 IRU COMPARTMENT REMOVED NR2 IRU FOUND FAN TO BE FROZEN ELECTRICALLY. REMOVED AND REPLACED NR2 IRU FAN WITH NEW REPLACEMENT UNIT, IAW MM 34-908. RE-INSTALLED ORIGINAL IRU AND PERFORMED OP CHECK OF NR2 IRU SYS IAW MM 34-909, SYS CHECKS GOOD. RE-INSTALLED ALL FLOOR PANELS AND MATS. 8/12/08.