What was found
AIRCRAFT WAS GROUNDED: RED UNLK ON LEFT MAIN LDG GEAR ON THE INSTRUMENT PANEL. L/G SYSDISAGREE ON ECAM. WHEEL PAGE SHOWS ONE GREEN AND ONE RED TRIANGLE FOR THE LEFT MAIN. RECYCLED IN AIR SEVERAL TIMES WITH NO SUCCESS. INFO: L/G DOORS ON LEFT MAIN WOULD SOMETIMES NOT COME UP. INTERMITTENT WHEEL N/W STRG FAULT AS WELL. FOUND L/H MLG DOWN LOCK SENSOR TARGET BOLT MISSING AND TARGET HANGING LOOSE (15GA). MAINTENANCE REPLACED L/H MLG DOWN LOCK SENSOR TARGET SCREWS AND SAFETIED IAW AMM 32-31-73.