What was found
STAB TRIM RUNAWAY NOSE UP AFTER TAKEOFF. RAN QRH. NOSE DOWN SWITCHES DID NOT WORK. DISC STAB TRIM + PULLED C/B'S PER QRH. DOWNLOADED FDR TO REVIEW FLT DATA IAW AMM 31-31-01. FOUND LEFT YOKE PITCH TRIM SWITCH INTERNALLY FAULTED. SWITCH MOVES STAB TRIM OPPOSITE OF SELECTION. REF MAINTENANCE WORK ORDER 200467 FOR ALL WORK PERFORMED. CHECKED SWITCH WIRING IAW WDM 27-41-00. CAPT PITCH TRIM SWITCH WAS REPLACED IAW AMM 27-41-05. HSTCU OPS CHECK GOOD IAW AMM 27-41-00. OPS CHECK GOOD.