As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A SCHEDULED INSPECTION, REPLACEMENT OF DUCT ASSY 6914070-67. WE NOTICED THAT THE HEAT EXCHANGER SIDE PLATE HAD 2 CRACKS ABOUT .35" LONG AND NONE ON THE OPPOSITE SIDE OF THE HEAT EXCHANGER. A NEW HEAT EXCHANGER WAS INSTALLED. PERFORMED A LEAK CHECK ON THE DEFECTIVE UNIT AND FOUND THE CRACKS EXTENDED INTO THE COOLING FIN AREA, WHERE THEY CAN NOT BE SEEN. A SERVICE CONDITON REPORT WAS SENT TO MFG UNDER NR 655726.