As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL410 CABIN ALT. LIGHT AND WARNING HORN ACTIVATED. PRESSURIZATION WENT TO AUTO FAIL. MANUALLY CONTROLLED CABIN VIA MANUAL OUTFLOW VALVE OPERATION. GEEN ALT. LIGHT ON PRESS CONTROLLER NEVER ILLUMINATED. R&R L/H PACK FLOW CONTROL VALVE PER AMM.