@silverseed 

Be sure the wireless switch is set correctly.

Are the LED lights for the wireless blinking?

You should contact support as a complete sudden unexplained loss of wireless is not a good sign.

@silverseed 

Is this a "WDR3600"?

There is a light on the Front Panel for Wireless, each band, are they ALL off?

Also, the back panel has a wireless OFF switch, maybe you changed that?

silverseed wrote

On my desktop I try to go into 192.168.0.1 and 192.168.1.1 and have no access. I did a hard reset to default factory settings and still nothing. Any ideas?

Is the Desktop wired to the router? If so, what is its IP Address? 192.168.0.x or 192.168.1.x?

No 'access'? I asume you don't see the Router GUI or did you get an error?

Power is ON

System is Flashing

2.4 Flashing

5.0 Flashing

Ethernet is ON or Flashing.

It is a N600 WDR3500

This computer is connected with Cat6 Ethernet (which is the one trying to connect to 192.168.1.1 and 192.168.0.1, I even try a wireless USB Antenna to no avail)

Cable to Router connected with Cat8 Ethernet

Phone doesn't connect

Alexa Echo doesn't connect

Daughter's phone doesn't connect

Wireless laptops do not connect

I did a factory default reset and still nothing.

@silverseed 

OK, model is similar. Not sure it is a US router though? Are you in the US?

The Wired PC, what is its IP Address? If on Windows, just run in a CMD prompt IPCONFIG /ALL and post it and the gate address. I'll assume you are able to use the Internet? I'm sort of wondering what you are connecting too? Is your modem a pure modem or a combo modem/router? At least for the wireless part?

All this just make sense to me?

Just how and with what are you trying to log into the router? Did you get an error? Have you tried a different browser?

My suspicion is the RESET changed the IP Address of the router, but you say you tried both 'normal' ones? Confusing?

Contacting Support might be the best way to go?