What was found
BOTH FMC PROMPTS DISAPPEARED ON PUSHBACK. CA'S VTK FLAG, MAP FLAG, RUNWAY FLAG, CAUTION LIGHTS ILLUMINATED. FMC SWITCH IN NORMAL. GROUNDED - YES. CONFIRMED FAULT, CURRENT STATUS PAGE SHOWS MAINTENANCE MESSAGE 34-61001 "FMC-1 HAS AN INTERNAL FAULT". ACCOMPLISHED B737-9 IFIM TASK 34-61-00-810-883, VERIFIED FMC-1 DEFECTIVE. REMOVED & REPLACED FMC-1 AND ACCOMPLISHED FMC SOFTWARE CROSSLOAD PER B737-9 AMM 34-61-00-470-802. PULLED & RESET C/B. VERIFIED CORRECT SOFTWARES PER APIC. PERFORMED FLIGHT MANAGEMENT COMPUTER SYSTEM OPERATIONAL TEST REF AMM 34-61-00-710-801, OPS CK NML. CONSULTED BOEING ENGINEERING & ALASKA TECH SERVICE, OK TO RETURN AIRCRAFT BACK TO SERVICE.