@Keelhaulers 

If you did a factory reset where the reset is held for 10 seconds, what should happen is all the LED lights should blink on, then off. If that did not happen, then the LEDs may have burned out.

Another setting which will turn them off is if night mode is enabled which you can find in Advanced > System Tools > Control LEDs.

I have the same issue on one of 3 C9's. Only the USB LED will come on when I have something plugged in there, but otherwise no lights. Everything else works fine. Have learned just to live with it.

My version of firmware does NOT inclide LED night mode.

@BobElectrician I have exactly the same issue on my Archer C9. When I power it on, the right hand three lights flash blue for a few seconds then they go out. Then the Internet (satellite dish) flashes orange for a couple of seconds and goes out. After that, nothing is lit at all although the router seems to be working ok. 

Weirdly, and possibly unrelated, today my router decided to reset itself and the WiFi passwords for both the 2.4g and 5g networks both reverted back to some random sequence of numbers. No idea why that happened.

@Keelhaulers Hi. Did you solve your problem? Mine Archer C9 V3 (EU) today, goes through the same problem! 

@usoliveira It's working OK except for the witness lights, so I am letting sleeping dogs lie.

@Sanghvi5m how do you resolve it?

@TomG Same issue with the lights. Exacly what you described. It randomly when to factory reset. Had to redo everything but other than that it works fine.. no lights also.

@TomG Same exacto sequence just starting happening to me yesterday! Did u ever resolve that issue? 

@Keelhaulers Try with the TETHER app... There, Go to the router picture then to Tools >  LED Control.. and there, check that LED STATUS is activated and Night Mode is not....