I have an AC1750 router and I also have a RE450 range extender. I bought the extender around 9 months ago and it worked fine, I stopped using it for a while and have now decided to use it again. 

I've followed the steps to connect but it doesn't work. I wait for the power light to be solid, click the WPS button on the router and then click the large button on the front of the extender. The circle around the button lights up briefly and then turns off...and then nothing. The only illuminated light on the router is the power light. 

I've tried resetting the extender several times but it just doesn't work. Do you think the extender has failed or am I missing something?