As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD SQUEAL FROM EITHER LEFT OR RIGHT FOWARD WINDSHIELD BEGINS AT DIFF P 8.0 AND DIMINISHES AT DIFF P 8.3 WILL CEASE AT DIFF P 0 + 7.9 OR LESS. PERFORMED PRESSURIZATION OF AIRCRAFT TO 8PSI DIFFERENTIAL PER AMM 05-53-00. FOUND NO LEAK OR SQUEAL AT THE WINDOW