ive got the same issue with my antminer s9 13.5 th/s
i tried upgrading the firmware, factory resetting it, i also tried to ping the Bitmain netword(6 packets transmitted, 6 packets received, 0% packet loss)
the lights on the ethernet port on the back of the miner seems to be normal
i also just realized that the small red light on the middle hash board is not on