What was found
FLT 917, NR 1 THRUST REVERSER LIGHT FLICKERED DURING TAXI OUT. RETURNED TO BLOCK. MEL’D NR 1 T/R IAW MEL 78-1-1, VERIFIED NR 1 T/R CLOSED AND LOCKED. PLACARD INSTALLED. MAINTENANCE FOUND PIN 16 ON CONNECTOR D4856P PUSHED OUT. INSTALLED PIN 16 INTO SPARE PIN NR 10 ON CONNECTOR D4856P AND D4856J. OPS CHECK OF NR 1 T/R PER AMM 78-32-01, PG 501 GOOD. MEL CLEARED, PLACARDS REMOVED. AIRCRAFT RETURNED TO SERVICE.