What was found
AIRCRAFT WAS GROUNDED: FLIGHT AIR RETURNED TO MIA ON ACCOUNT OF NAVIGATION ISSUES AND NOISES FROM THE AVIONICS BAY. AN EMERGENCY WAS DECLARED. MAINTENANCE GAINED ACCESS TO E&E BAY. CHECKED EQUIPMENT FOR SECURITY. PERFORMED GVI OF E&E BAY. FOUND NO OBVIOUS SIGNS OF DAMAGE OR LOOSE EQUIPMENT. ACCOMPLISHED A RETRACTION AND EXTENSION OF NOSE GEAR NO ABNORMAL NOISE NOTICED IAW AMM 32-33-00. ACCOMPLISHED TASK 32-51-00-810-801 UP TO STEP E3, REMOVED AND REPLACED BOTH NOSE WHEEL SPIN BRAKE LININGS IAW AMM 32-45-31. ACCOMPLISHED BITE CHECK, FOUND MSG 22-11004. COMPLETED TEST ON ADIRU, FOUND FAULT ON LAST FLIGHT LEG. REPLACED LH ADIRU, COMPLETED OPS CHECK IAW FIM 22-11-00 AND AMM 34-21-00.