What was found
IN FLIGHT AVIONICS SMOKE MASTER WARNING LIGHT CAME ON. RAN MEMORY ITEMS AND QRH CHECKLIST. LIGHT REMAINED ON DURING FLIGHT AND EXTINGUISHED AFTER LANDING NO ACTUAL SMOKE OR FIRE DETECTED. DIVERTED FLIGHT TO ATW. MAINTENANCE DEFERRED AVIONICS RACK SMOKE DETECTION SYSTEM PER MEL 26-13-3-B. ENTERED INTO DMR MXC NOTIFIED. MAINTENANCE PROCEDURES C/W. MAINTENANCE REPLACED AVIONICS SMOKE DETECTOR.