What was found
(CAN) DURING CLIMB, YAW DAMPER WAS AUTOMATIC DISENGAGED WHEREBY WE ALSO RECEIVED AN AUTOPILOT FAILURE. THIS WAS FOLLOWED BY ATTITUDE FAIL, IVSI FAIL AND HDG FAIL ON PFD NR 2 (AHRS 2 FAILURE). CLIMB WAS STOPPED AT FL120, A/C RETURNED FOR LANDING. DURING RETURN FLIGHT ALL THE FAILURES CAME AND WENT SERVAL TIMES INDICATING A LOT OF CAUTIONS AND AURAL ALERTS. INVESTIGATION/ACTIONAFTER THIS OCCURRENCE, THE AHRU NR 2 WAS REPLACED. THE FAULT WAS CONFIRMED AT THE SHOP, IT WAS FOUND TO BE THAT ONE CAPACITOR ON THE POWER SUPPLY BOARD HAVE DEVELOPED LEAKAGE AT HIGH TEMPERATURE AND/OR AGING.