What was found
MULITIPLE MCP/AP/FD FAILURES. ON TAKEOFF, WHEN V NAV SELECTED AIRPLANE WENT INTO GA MODE. DURING APPROACH IN VMC AT DFW, AP KICKED OFF. NO FLT DIRECTOR, INTERMITTENT RAW DATA WAS VISIBLE. DURING DIVERT, ALL MODES RECOVERED AND FAILED MULTIPLE TIMES. DURING ANY ALTITUDE CAPTURE THE FAILURES WOULD OCCUR. THERE WAS NO OTHER INDICATIONS OR INDICATIONS. EMERGENCY DECLARED. DIVERTED TO SAT. REMOVED & REPLACED FCC-B COMPUTER IAW AMM 22-11-33. PERFORMED BITE TESTS. ALL TESTS OK.