What was found
(CAN) ON APPROACH, WHEN CREW SELECTED FLAPS TO BE EXTENDED BOTH AUTOPILOT SYS, A AND B DISCONNECT. ACFT IS OPERATING UNDER MEL WITH TROUBLESHOOTING UNDERWAY BY MAINTENANCE PERSONNEL. MORE DETAILS TO FOLLOW WHEN TROUBLESHOOTING IS COMPLETE. UPDATE INFO: MAINTENANCE PERSONNEL CARRIED OUT TROUBLESHOOTING OF AUTOPILOT SYS AND AUTOPILOT FOUND FLAP SWITCH, PN 426EN10-8 TO BE AT FAULT. THE FLAP SWITCH WAS REPLACED IAW AMM 22-11-36 AND NO FURTHER FAULTS WERE NOTED.