As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PUSHBACK THE LEFT PACK FAN POPPED TWO CB''S. FOUND LT HEAT EXCHANGER WIRES SHORTED. WIRES CAPPED AND STOWED AND SYSTEM PLACARD. *S/D* FOUND THE PACK COOLING FAN WIRES WERE CHAFING AGAINST THE HEAT EXCHANGER HOUSING. WIRES WERE SPLICED AND SYSTEM REACTIVATED.