As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT, PRESSURIZATION PANEL HAD A AUTO FAIL AND ALTN LIGHT ON WITH SWITCH IN AUTO. ACFT GROUNDED. CYCLED THE SWITCH TO MANUAL AND BACK TO AUTO. NO LIGHTS ILLUMINATED. NR 1 AND 2 PRESSURE CONTROLLERS BITE AND OPS NORMAL. NO CURRENT FAULTS FIM 21-31 TASK 827 AND 21-31 TASK 801.