What was found
SEVERAL INTERMITTENT PRESSURE CONTROLLER AUTO FAIL/ALTN LIGHTS COME ON. TWO SECONDS THEN WENT OUT. ACFT GROUNDED. PERFORMED FIM 21-31, TASK 827. BITE CHECK PRESSURE CONTROLLER NR 1 & NR 2 IAW FIM 21-31, TASK 801. NO CURRENT FAULTS AND NO FAULT HISTORY FOR FLT LEG 01. ALSO PERFORMED ADIRU NR 1 & NR 2 BITE CHECK IAW FIM 21-31 TASK 806. NO CURRENT FAULTS AND NO FAULT HISTORY. PRESSURIZATION SYSTEM GROUND TEST REF AMM TASK 21-31-00-700-802. DURING TEST CONTROLLER NR 1 FAULTED. TIGHTENED CONTROLLER NR 1 IN RACK AND PERFORMED OPS CHECK WAS GOOD. NO FAULTS FOR CONTROLLER NR 1 OR NR 2.