What was found
STBY RUDDER FAILS TO OPERATE PUMP COMES ON WITH A, B AND ALT FLAP SWITCHES RUDDER FAILS TO MOVE EITHER RIGHT OR LEFT TROUBLESHOT PER FIM FOUND STBY HYD SYSTEM MODULE INOP. REMOVED AND REPLACED HYD MODULE PER 29 21-51-400-801 OPS CHECK GOOD LEAK CHECKS GOOD, RUDDER OPS GOOD. ROTABLE PARTS CHANGE WAS INDICATED - TT # 1426738 SN OFF 06315 IPC REFERENCE 29-21-51-400-801 PACKAGE, HYD, S OFF 29-2921-9-0003 6315 ON 29-2921-9-0003 3474 (NOTE - THE PROBLEM WAS FOUND DURING THE PRE-FLIGHT TEST ACCOMPLISHED BY THE FLIGHT TEST CREW).