What was found
DURING DESCENT WIND FORECAST UPLOAD, BOTH CAPT & FO ND'S WENT BLANK VDK ANNUNCIATED ON CAPT. ND BOTH MCDU'S WENT BLANK. AFTER APPROXIMATELY 30 SECONDS EVERYTHING RESTORED TO NORMAL. GROUNDED - YES. FOUND MAINT MSG 34-69001, UNDER GRND FLT DECK EFFECTS, NO MAINT LIGHT. ACCOMP FMC OP'S CK, REF B737-9 AMM 34-61-00-710-801 & MAX DISPLAY OP'S CK REF AMM 31-65-11-400-801 'H', NO DEFECTS FOUND. A/C OK FOR SVC.