As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING RECEIVING INSP OF O/H PRESSURE CONTROLLER AND BEFORE INSTALLATION, FOUND THE "CAB ALT" KNOB BINDING INTERMITTENTLY AND MAKING A RATCHETING NOISE WHEN ADJUSTED. PART WAS NOT INSTALLED ON ACFT. NOTIFIED THE VENDOR THAT THE PART WAS PURCHASED FROM. PLACED AN ORDER FOR A DIFFERENT CONTROLLER.