flashing lights laserjet pro m404n nothing in manual or chatbot

[laserjetprom404]

Two flashing lights, a green semi circle together with an orange triangle and exclamation point.

Have replaced cable, unplugged and plugged, restarted power on both machine and printer.

It used to work fine ...   Unable to find the meaning of these lights anywhere.  Tried the chatbot.

Looked in manual.

I found a similar error message here and the HP reply was we have never had that problem although

we have made over a million of these printers.... OK, well here's another printer with the same error.

[Repairatrooper]

Both lights blinking at the same time indicate that the printer is initializing. If those lights never clear it would suggest that the printer cannot complete startup for some reason. In your position I would try to perform a factory reset on the printer to see if the error clears.

[laserjetprom404]

Indeed, the printer is having problems, not starting up.    

I think it could be toner.  we'll find out.

too bad there isn't a text message or self debugging.

[Repairatrooper]

Are you able to connect to the printer over the network, you might find an error code that way.