As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TRANSIT CHECK, DURING PREFLIGHT PROCEDURE THE FLIGHT CONTROL LOW PRESSURE LIGHT TURNED OFF IN THE CHANNEL B. PERFORMED FIM 27-21 TASK 814 PROCEDURE, DETECTING THE LOW PRESSURE WARNING SWITCH OF SYS B WITH FAILURE. THE LOW PRESSURE WARNING SWITCH WAS REPLACED IAW AMM 27-09-61, TESTED CORRECT.