As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER REACHING CRUISE ALTITUDE OF FL410, AN AUDIBLE POP WITH ASSOCIATED RISE IN CABIN PRESSURE OCCURRED. CREW DESCENDED AND CABIN ALTITUDE AMBER CAS DISPLAYED AND QRH WAS ACCOMPLISHED. ACM O'HEAT AND HEAT EXCHG ONLY DISPLAYED UNTIL QRH PROCEDURE CLEARED MESSAGE. LANDED WITHOUT FURTHER ISSUE. PRESSURIZATION SYSTEM WAS CONSIDERED INOP BY THE FLIGHT CREW (RAPID DEPRESSURIZATION). UPON INSPECTION OF THE SYSTEM, FOUND THE MIXER ASSY FAILED AT A FACTORY WELD (ABOUT 2/3RDS AROUND THE ENTIRE PERIPHERY).