What was found
AIRCRAFT NOT GROUNDED: PILOT REPORTS UPON LEVELING AT 10000, HEARD LOUD CLICK BEHIND F/O . AT SAME TIME CAPT PFD, ND, BOTH EWDS HAD A WHITE DIAGONAL SLASH MOMENTARY. IMMEDIATELY EVERYTHING RETURNED TO NORMAL. MAINTENANCE COULD NOT DUPLICATE ON GROUND. RESET DMC 1,2,3 IAW AMM 31-60-00. PERFORMED TEST OF EIS IAW AMM 31-60-00-710-001-A NO FAULTS NOTED.