As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT HEARD LOUD NOISE AND CABIN CLIMBED, UNABLE TO MAINTAIN CABIN PRESSURE. ENTERED ON DMI NR 17926 IAW MEL 21-65 CAT "C" PLACARD INSTALLED. FOUND VENTURI SENSING LINE BROKEN. REMOVED AND REPLACED SENSING LINE IAW STC ST466CH; PERFORMED OPERATIONAL CHECK ON GROUND FOUND NORMAL IAW STC ST466CH. CLEARED DMI 17926.