What was found
AFTER PUSHBACK, JUST AFTER DISCONNECT FROM TUG WITH PROPS AT FEATHER THE NLG DOOR OPENED & AFTER 30 SECONDS IT CLOSED AND THEN TAXIING OUT, NLG DOOR SEQUENCED AGAIN. RETURNED TO GATE. DISCONNECTED FWD LT NLG DOOR PUSHROD & REMOVED GRAVEL GUARD FOR TROUBLESHOOTING. FOUND NLG DOWN 2 PROX SENSOR TARGET LOOSE. RETORQUED & SAFETIED TARGET, REF AMM TASK NR 32-21-06-400-801, PARA 4A, STEPS 1 (J) THROUGH 1 (L). VERIFIED PROX SENSOR RIGGING & INDUCTANCE VALUE IAW AMM TASK NRS 32-61-06-830-801 & 32-61-00-280-801. RE-INSTALLED GRAVEL GUARD & RECONNECTED LT FWD NLG DOOR IAW AMM TASK 32-22-11-400-801, PARA 4A STEPS (15) THROUGH (19). NO ADJUSTMENTS WERE MADE TO PUSH ROD. RETURNED TO SERVICE.