There are other threads with many having the same issue. I am also. Too many with the same issue for it to be a machine problem. It has to be something Canon sent down or a bug.
This started tonight on my MG6620 also. Turn the printer on, stays on for a few seconds then shuts down. Never get the printing screen to come on and not able to get into the settings to reset them. Tried a few time to reset to no avail. Funny I ...