I bought refurbished Xbox One from Gamestop for my son for Christmas. After using it for three months he tells me the controllers continuously disconnect from the unit and always have. At this point we're two months past the 30 day return period... and Gamestop was of no help whatsoever. Someone with far more computer repair experience than me told I needed to replace the wi-fi card. Made sense to me. So I came here and ordered a wi-fi card, tools, (and a cable just in case).
The repair went very well. Sort of. The instruction guide on here was great. I dismantled the Xbox and replaced the wi-fi card with no issues. I didn't put the cable in because I couldn't find an instruction set for how to do that and that repair seemed significantly more intrusive. Problem is... replacing just the wi-fi board did not resolve the issues; controllers kept disconnecting as bad as before, and I still had a frustrated pre-teen with a bum Christmas present. But then I found an Xbox One tear down guide that showed me the one extra step I needed to do to replace the cable... so I took the Xbox apart. Again. Cable installed. X-box reassembled. Bickety Boom! I fixed it! No more controller disconnects (knock on wood). I remain cautiously optimistic that the problem has been solved. Probably just the wi-fi cable all along!
Once you follow the guide on how to open the Xbox enough to install the wi-fi card, there are just (8) torx head screws to remove in order to open the metal case and swap the wi-fi cable. If you're in there so far already you might as well because the part was like $5 and replacing it seemed to have solved the issue (at least in my case).