As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT INSTRUMENT AIR PRESSURE WAS AT ZERO ON THE GROUND AND WOULD INCREASE AS CABIN PRESSURE INCREASED IN FLIGHT. FOUND PNEUMATIC SUPPLY LINE FROM COMMON TEE TO FORWARD PRESSURE BULKHEAD MELTED. REPLACED TUBING WITH SUPERSEDED (PN P610051) TWICE. BOTH TIMES THE LINE MELTED ON POWER APPLICATION.