What was found
LNAV AND VNAV WILL NOT ARM ON THE GROUND. GROUNDED - YES. DFCS BITE TEST SHOWS "LNAV ENG FMC DATA INV, CHAN-B MCP, MSG# 22-11822. ACCOMPLISHED B737-800 FIM 22-11 TASK 811 FMC FAULT ISOLATION. REMOVED & REPLACED FMC #2 REF B737-800 AMM 34-61-02. PULLED & RESET 2 TOTAL C/BS. ACCOMPLISHED CROSS-LOAD SOFTWARES, PERFORMANCE FACTORS, & CURRENT FMC NAV DATA, OPS CK NML REF AMM 34-61-00-710-801. ALSO, ACCOMPLISHED MCP TEST & PUSH-BUTTON TEST REF AMM 22-11-34, OPS CK NML.