What was found
(CAN) WHILE IN CRUISE AT FL390, ACFT LOST ENTIRE AUTO-PILOT, AND PITCH TRIM CAPABILITIES. ACFT DECLARED A "PAN PAN" WITH ATC. ACFT MAINTAINED ALTITUDE WITH FAILURE +/- 100FT. ATC BLOCKED AIRSPACE BETWEEN FL390-370. FIM TASK 27-43-00-810-801-A CARRIED OUT, FAULTS CLEARED. MOC HSTA MOTOR CHANNEL 1 REPLACED IAW AMM 27-43-03-400-801-A AND REPLACED CHANNEL 1 RESOLVER IAW 27-41-01-000-802-A. SYSTEMS TESTED SERVICEABLE.