One evening I took my Xbox into my bedroom (directly under the router) to play but the controller kept disconnecting and reconnecting. Eventually it worked again and all was well, until the next day. The next day I took it back to the living room to play when the controller repeated the same disconnecting and reconnecting, except this time the Internet would disconnect as well. This happened every 10 seconds or so. I plugged the Xbox into the router and this fixed the Internet, but not the controller. The wired controller I had would constantly drift (it wasn't my controller so not my problem). The Xbox was pretty much unplayable. From there I diagnosed a problem with the Wi-Fi board, but I was only 50% sure because this is my first Xbox console and I haven't had it very long (maybe a year and a half).
The repair went incredibly smoothly. The instructions are very easy to follow (I struggle with written instructions sometimes because of my Aspergers) and I had no problems getting the console apart or putting it back together again.
I didn't have a plastic spudger so I used a plastic opening tool for the entire job. I wouldn't recommend doing this because the plastic opener is now pretty much chewed up and another one snapped. As the guide says, make sure you keep the spudger (or in my case, opening tool) wedged into the box. Mine fell out once and I ended up catching my fingers in the casing. Also, take it slowly- I actually cut my hand on a sharp bit of plastic on the inside somewhere. Don't be afraid of using force on the plastic, and don't be alarmed if the hinges make loud snapping sounds.