What was found
AT 7,000-FT, IFR AND IMC, IN LEVEL FLIGHT AT 115 KNOTS, ENROUTE, ACTUATION ILLUMINATED AND PITCH MODE FAILED. MAINTAINED CONTROL OF ACFT PITCH CHANNEL AND ALLOWED NAV MODE TO CONTINUE NAVIGATION. FAILURE OCCURRED IN RELATIVELY SMOOTH CLOUD FORMATIONS AT 7,000-FT WHILE AT LEVEL CRUISE. FAILURE PERSISTED UNTIL LANDING. FLEW THE ACFT MANUALLY, REQUESTED PRIORITY HANDLING AND SPACING FROM APPROACH & MVA, THEN CANCELED IFR, THEN PROCEEDED VFR TO 09TN. THE ACFT WAS INSPECTED AND NO FAULT WAS FOUND, NOR ABLE TO BE DUPLICATED.