What was found
DURING APPROACH INTO BWI, SLAT BLUE EXTEND LIGHT DID NOT ILLUMINATE AFTER SLAT EXTENSION. PERFORMED GO-AROUND PROCEDURES AND RECYCLED SLATS, STILL NO BLUE LIGHT. FIRST OFFICER VISUALLY CONFIRMED SLATS TO BE EXTENDED. SUCCESSFUL LANDING WAS ACCOMPLISHED USING NO SLATS PROCEDURES. RESEATED CANNON PLUG ON RIGHT SLAT EXTEND SWITCH. OPERATIONAL CHECK OK, AIRCRAFT RETURNED TO SERVICE.