What was found
DURING APPROACH LOWERED FLAPS TO 15` AND STAB MISCOMPARE CAUTION LT ILLUMINATED. VERIFIED DISCREPANCY. STAB DID NOT MOVE WHEN FLAPS WERE LOWERED AND RAISED. ACCESSED TWO POSITION TAIL ACB AND SPEED SWITCH IN CO-PILOTS SIDE CONSOLE. CHECKED VOLTAGE AT PIN 1 OF PCB N2017 VOLTAGE WAS 0.016 S/B 28 VOLTS. TAPPED SPEED SWITCH AND GOT 28 VOLTS. REMOVED FAILED AIR SPEED SWITCH. INSTALLED NEW SPEED SWITCH. PERFORMED OPERATIONAL CHECK. OPERATIONAL CHECK GOOD. ALL MAINTENANCE DONE IAW MM 27-40-01.