As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, WHILE AT FL380, RECEIVED CABIN ALT WARNING LIGHT AND WARNING HORN. LT BLEED DUCT PRESSURE 40 PSI. RT BLEED DUCT PRESSURE 0 PSI. DESCENDED AND MASKS DID NOT DEPLOY. ACFT DIVERTED. MAINTENANCE FOUND CIRCUIT BREAKER B7 ON THE P6-4 PANEL OUT. INSPECTED NR 2 PRSOV AND PERFORMED TASK AMM 36-00-00-860-804. OPS CHECKS OK, ACFT RETURNED TO SERVICE.