As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT ARRIVED AT GATE AND APU WOULD NOT POWER AC BUS. RIGHTHAND BUS TIE IS OPEN AND WILL NOT CLOSE. *S/D* THIS REPORT IS DIRECTLY RELATED TO REPORT 99UAL900166 RELATED. REFER TO 99UAL900166 FOR THE DETAILS RELATED TO CAUSE AND CORRECTIVE ACTION. THE LOSS OF ELECTRICAL SIGNAL DUE TO WIRE DAMAGE GAVE NON-VALID SIGNALS TO THE AIRCRAFT ELECTRICAL POWER SYSTEM LOGIC ASSOCIATED WITH THE APU (AUXILIARY POWER GENERATOR) POWER AVAILABILITY.