Connecting Wireless MY Notebook to My new 55 inch Samsung HDTV

I just got a new Samsung TV. When i first began to use it, it picked up my media server from the WD My Passport. Then one day it just stopped and won’t show up when I change sources. I know it’s not my WD Passport, because I access it via my computer. Can anyone guide me in the right direction? I’d like to go direct vs. using my PS3. 

I’d look into what may have happened with either the media server or your network.  have you made any changes to either?