Additional possible fixes for some users
So this may not work for everyone but here's some more possible solutions I've came across in addition to my previous posts on this thread:
http://support.apple.com/kb/TS3125
trouble shooting software issues (3rd party)
Try turning off Home Sharing in iTunes. Then turn Home Sharing back on. This time don't click on done in the last step. Try clicking on My Music instead. By just clicking My Music instead, Home Sharing would stay in place and Apple TV may work. - From Apple Support Community
For those with issues with Apple TV dropping WiFi connection: I checked the logs and noticed the WGA Key timeout coincided with the TKP rotation. Which matched the time the ATV dropped Home Sharing. I had the timeout key to default 1 hr, I have now changed it to several days. - From Apple as well, sorry don't have some of the links handy.
http://support.apple.com/kb/HT1925
removing itunes and related componets, will not remove your library FYI
http://support.apple.com/kb/HT3204
diagnostics
Highly Recommend following this
Some users had issues with Avast antivirus and disabling didn't fix however uninstalling did fix their issue.
Make sure you don't have two firewalls going:
I accessed windows firewall exceptions and noticed that Itunes wasn't selected, I selected Itunes, restarted all my devises and bingo, its all back up and running, if your unsure how to access the firewall settings here's what you do.
Control panel
- security
- windows firewall
- select change settings
- Exceptions tab
- scroll down to itunes and make sure it is selected.
--From Apple as well
Linksys routers:
I just got off the phone with Linksys tier 2 tech support and I finally have a work around that is different from what everyone else has been doing and ostensibly we don't have to sacrifice anything.
Applications & Gaming -> QoS -> WMM -> ENABLE IT
Administration -> Management -> CTF -> DISABLE IT
Also make sure that both the AppleTV and the computer are on the same Wifi network. Check your router status menus for list of connected devices, this will also let you know if they are at least on the network (even if you have just one).
Lastly (for now) try this link:
https://discussions.apple.com/thread/3461734
Screenshots of all the places homesharing must be turned on.
If all else fails call: 800 APL Care
Also let us know what works if you find a solution. If not it helps to know a little about your home PC (win or mac and version), router, and if homesharing with other devices works (can iphone see ur pc itunes library?).
Thanks
Edit: added Official Airplay troubleshooting
http://support.apple.com/kb/TS4215
&
For those extremely rare situations:
Check for interference on your network using istumbler.net (netstumbler for windows)
2nd edit:
Make sure Home sharing is enabled in both the Music AND Video settings on you iPhone/iPad.
Until tonight my iPad Remote wasn't connecting to my Apple tv but my iPhone was due to this.