What was found
DURING APPROACH, THE LEFT MAIN GEAR INDICATED A YELLOW HASH UPON EXTENSION. WE WENT AROUND AND DID THE GEAR DISAGREE LEFT CHECKLIST AND THE LANDING GEAR WILL NOT EXTEND CHECKLIST. NEITHER CAUSED THE GREEN DOWN TO ILLUMINATE. AS A RESULT THE GEAR BLOWDOWN PROCEDURE WAS UTILIZED. CORRECTIVE ACTION: ACCOMPLISHED ADJUSTMENT AND OPERATIONAL CHECKS ON THE LEFT MAIN LANDING GEAR UPLOCK SWITCH IAW MM 32-32-25. OPERATIONAL CHECKS WERE GOOD. REFERENCE ORDER NUMBERS 101718284, AND I OJ 718285 OF THIS REVISION FOR FURTHER DETAILS.