C3700|N600 Cable modem wifi router. 1.y years old. It suddenly stopped working. When switched on power light is getting on (green) and nothing happens then after a while (may be 30 secs) all the lights flash and goes off then power stays on. The router stays on like this (periodic flashing of all the lights). In this state the router is not accessible with either by network cable nor by WiFi and there is no internet connectivity as well.
This problem was occuring once in a while and then it got resolved automatically i.e. if you switch it off and leave it like that for hours and switch it on then some time it worked earlies. But now it stopped working completely and it exhibits the above mentioend behavior consistently and not going back to the working state.
Whether it indicates the firmware got corrupted and it need to be reinstalled. If yes how to do that? Factory reset and power cycle did not help. The behavior remains the same (i.e. power on, periodic flashing of all the lights but no internet, no WiFi and no connectivity to the modem/router).
