B737-700
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue
Flight Crew Executed Go Around / Missed Approach; Flight Crew Overcame Equipment Problem
Aircraft
Enroute; left flaps transit light; with 3D LED on right wing annunciator. Complied with QRH and contacted Dispatch via ACARS. During coordination with Dispatch the light went out. Approach: All normal (no lights) visual flaps 30. After completely configured for landing flaps 30 and slowing to target airspeed at around 1;500 feet AGL at about 155 knots IAS we received stick shaker; followed by 'Airspeed Low' voice indication. We immediately did a full power go-around. I noted that the HUD; my Primary Flight Display (PFD); FO PFD and standby; all said same airspeed. After clean-up from go-around; the same leading edge extension light came back on as before.Downwind vectors: Repeated QRH steps. As per QRH; set up for a flaps 15 landing. This time I did not communicate with Dispatch due to time constraints with three page QRH procedure and lots of Approach Control issues. While being vectored around; I discussed with FO that if we received stick shaker again that we would both confirm and verify that all airspeed indications are correct and if so that we would continue the approach. My feeling is that going around and doing it all again was not going to fix anything; and a third time vectoring around could make fuel a problem.Final: Flaps 15 fully configured. At same airspeed as first approach 155 knots; again received stick shaker. This time though it was about same as target airspeed (because of QRH flaps 15). I double/triple checked all airspeed indications. Also aircraft attitude and engines were normal. Before I could verify with FO; the stick shaker quit and all seemed normal. We elected to continue to a normal flaps 15 landing.Post Flight: Maintenance met us at gate; first check they did was stick shaker check; and the check failed.
B737-700 Captain reported that after running the QRH for a left flaps transit light they received a stick shaker on approach that was later traced to a malfunctioning stall warning system.