@lennylion 

Hello Lennylion,

Can you be more specific about the device model details please?

Have you setup timings for the LEDs on the device to remain off (i.e. at night)?  If you have, then I suspect this is what is happening. When you switch a router on, it defaults to a time of midnight, on whatever date is set as the default date when the device was manufactured. This will then trigger the LED illumination rules if any have been set. Shortly after the router makes a connection with your service provider's network, it will obtain the correct time from an NTP time server, and set the LEDs accordingly. Assuming you've set them to be on during the day, they will come on once the correct time has been set. I stopped breathing when that happened to me, until I joined up all the dots!  :-)

One last point about the router; it is generally best to leave these devices on; frequent power cycles can lead your service provider to reduce line speed, as that behaviour can look like a device unable to cope with current line speeds. If electricity supply is a problem in your part of the world, then I understand why the unit needs to be turned off.

If the above isn't the issue, the only advice I can give presently is to factory reset it and go through the setup procedure again.

I hope this helps!

Mike