As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL - FLT 79 - AFTER TAKEOFF, RIGHT FORWARD DOOR ANNUNCIATOR LIGHT ILLUMINATED. AIRCRAFT WOULD NOT HOLD PRESSURIZATION. FLIGHT RETURNED TO PHL AND LANDED WITH NO FURTHER INCIDENT. MAINTENANCE FOUND THE DOOR SEAL LOOSE AND IN THE DOOR TRACK. SEAL WAS REINSTALLED. (M)