As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING BASIC INSPECTION, TECHNICIAN FOUND THE COCKPIT FIRE EXTINGUISHER PRESSURE GAUGE TO BE READING AT VERY BOTTOM OF GREEN RANGE. FURTHER INSPECTION REVEALED THE GAUGE TO BE LOOSE, AND SLIGHTLY TWISTING GAUGE CAUSED THE BOTTLE TO LEAK.