As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORDERED IN A WARRANTY EXCHANGE UNIT FROM ACFT MFG AND WERE SENT A REPLACEMENT GAUGE 2/22/2011, SN 864BA. THIS UNIT WAS O/H REF WO 0364333 BUT WHEN INSTALLED, THE LOWER HALF OF THE BACKLIGHTING IAW INOPERATIVE. TROUBLESHOT THE BACKLIGHTING WIRING AND DETERMINED THAT THE FAULT WAS INTERNAL IN THE INSTRUMENT.