What was found
DURING TOUCHDOWN AND ROLLOUT, BOTH FMC'S BLANKED OUT - NO "FMC" PROMPT ON MCDU'S AND WE HAD A AMBER FMC WARNING ON BOTH FORWARD INSTRUMENT PANEL WARNING LIGHTS AND NO WARNINGS ON FLIGHT OR NAVIGATIONAL DISPLAYS. GROUNDED - YES. FMCS BITE TEST SHOWS L/H FMC FAULT ON INBOUND LEG. ACCOMPLISHED "FMC HARDWARE/SOFTWARE FAULT ISOLATION" REF B737-900 FIM 34-61 TASK 807, OPS CK NML. GVI BOTH FMCS FOR SECURITY, NO DEFECTS NOTED.