Wifi Timeout @ 5GHz

My Macbook Pro is on Version 10.9.1 aka Maverick and whenever I try to connect to the 5GHz Wi-Fi it timeout for some reason. When I connect to the 2.4GHz Wifi it works just fine. I was able to log into the 5GHz Wi-Fi last year without any problems until yesterday. It is mostly a wired Ethernet connection to the router. My router is an ASUS RT-N66U.

I have followed Apple's troubleshooting guide and . The link is down below:

http://support.apple.com/kb/HT4628?viewlocale=en_US

I even looked at this Discussion from 2012.

https://discussions.apple.com/thread/4206528

In addition, I tried following this guide as well, but no luck.

https://discussions.apple.com/thread/5470945?tstart=0

I thought it was a problem with my 5GHz part of the router, but I connected with my Windows to it without problem. Any suggestions?