As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A SCHEDULED INSPECTION, NOTICED THE HEAT EXCHANGER SIDE PLATE HAD THREE CRACKS ABOUT .30 INCH LONG. OPPOSITE SIDE OF THE HEAT EXCHANGER WAS CRACKED IN THREE OF THE FOUR CORNERS. A NEW HEAT EXCHANGER WAS INSTALLED. PREFORMED A LEAK CHECK ON THE DEFECTIVE UNIT AND FOUND THE CRACKS EXTENDED INTO THE COOLING FIN AREA, WHERE THEY CAN NOT BE SEEN.