As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACFT WAS ON CLIMB-OUT FOR A TEST FLIGHT BEING PERFORMED, THE RT BUSS FAILED. THE RT TRU, RT STALL WARNING AND RT ELEVATOR HORN HEAT ILLUMINATED. MX FOUND THE RT PROPELLER BRUSH BLOCK SEVERELY WORN. THE BRUSH BLOCK WAS R & R. PERFORMED GROUND MX RUNS, AND SYS PERFORMED SATISFACTORY. ACFT WAS RETURNED TO FLIGHT STATUS.