Hi. I came home one day and my router was dead. No lights on any ports and couldn’t connect to it. I pressed and held reset button to do a factory reset and then it came up with factory defaults. Reconfigured and life was good. I took a backup this time in case I needed it.
So had to tidy up some wires and power came unplugged. Same thing happened again. All the port lights come on for a while then they got back off after a few seconds and dead again. Did a reset and logged back in and restored backup, same issue again all lights come on and then go back off. I had to reset again and configure manually.
As I recall, the reset button also engages the backup bootloader. If you can get the router to bootup when using that button to return to factory defaults, but it won’t come up when rebooting normally, then my guess is that your primary bootloader is corrupt. Try a “/system routerboard upgrade” while the device is running and then try rebooting normally after that.
If that doesn’t fix it, my next recommendation would be to perform a Netinstall.