As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSTALLED REPAIRED PRESSURIZATION CONTROLLER PN 13300-020, SN 1574 INTO N720JC, SN 273 ON 01-07-2009. THIS CONTROLLER IS CAUSING THE OUTFLOW VALVE SOLENOID TO CHATTER WITH GROUND POWER APPLIED. THIS UNIT WAS REPAIRED , TRACKING NR 61977 DATED JUNE 15, 2007. SIMILAR DEFECTS HAVE BEEN AN ONGOING ISSUE WITH THESE PRESSURIZATION CONTROLLERS.