What was found
STAB TRIM LITE ILLUMINATED IN FLIGHT WITH A SPEED TRIM FAILURE BOTH AIRCFAFT HAD TO BE FLOWN BY HAND NO AUTOPILOT PERFORMED STAB TRIM TEST, COLUMN SWITCHING MODULES AND NEUTRAL SHIFT SENSOR FAILED SEVERAL TIMES. FURTHER T/S REQUIRED. REF L/P 8537413, FOUND PHASE B MISSING FROM CB C3001. R&R''D CB C3001, PERF''D DFCS OPS TEST FOR STAB/SPEED TRIM SYS IAW AMM 22-11-00-740-801. ALL TESTS PASS, NO FURTHER DEFECTS NOTED. OK TO CONTINUE.