What was found
RIGHT BLEED TRIPPED RESULTING IN A LOSS OF CABIN PRESSURE. *S/D* WHEN THE RIGHT HAND PACK TRIPPED OFF, THE ISOLATION VALVE OPENED AND BLEED AIR SUPPLIED FROM THE LEFT HAND PACK ENTERED INTO THE RIGHT SIDE OF THE PNEUMATIC MANIFOLD. A HOLE WAS DETECTED IN THE SENSE LINE CONNECTING THE PRESSURE REGULATING AND SHUTOFF VALVE TO THE 450 THERMOSTAT. THE SENSE LINE WAS REPLACED.