As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WE SENT IN BOTH AIRCRAFT PFD'S FOR REPAIR AND SB COMPLIANCE. BOTH UNITS WERE REPAIRED AND REINSTALLED. WE TRIED TO CALIBRATE THE ADHRS AND THE PILOT PFD CONTINUED TO GIVE AN ERROR. WE SPOKE WITH ANOTHER SHOP AND WERE TOLD THEY HAVE HAD THE SAME PROBLEM. IN FACT, WE WERE TOLD THEY NORMALLY HAVE PROBLEMS WITH REPAIRED UNITS (ABOUT 50 PERCENT OF THE TIME).