 After retirement, parts of trains 1-72 and 1-73 were used on the Yeongdong Line for testing in mid-2017 before being stored out of service again.In a surprise move, cars 1673 and 1773 were brought back into service in March 2019, when they replaced two powered cars in train 1-79.The cars were retired again in mid-November 2019 when train 1-79 was retired, marking the end of service life of the second generation trains.