What was found
WHILE AT CRUISE, FL380, LNAV VNAV ENGAGED, VTK DISPLAYED ON CAPT ND, FOLLOWED BY BOTH CDU'S BLANKING, 15 SECONDS LATER #1 FMC RESTORED TO NORMAL OPS BY ITSELF - DID NOT POSITION FMC SWITCH TO BOTH ON R. GROUNDED - YES. REF B737-800 FIM 34-61 TASK 836. INITIAL EVALUATION SHOWS INTERMITTENT FAULT. FAULT LEG 01 SHOWS CDU POWER SUPPLY 85214.3. ACCOMPLISHED FMCS BITE PROCEDURE TASK 801. NO FAULTS CURRENT. ACCOMPLISHED FMCS OPERATIONAL TEST IAW B737-800 AMM 34-61-00-710-801. GROUND VERIFICATION TEST IS GOOD.