I have a Time Capsule running the firmware version 7.6.1 (the latest) and today for some reason the 2.4 GHz wireless signal stops works and disappears (the signal no longer appears in the list of available netowrks on my iMac or iOS devices). The 5GHz signal remains and does just fine. When I cycle the power on the TC with about 30 sec downtime before powering back on the 2.4 GHz signal comes up just fine; however, after about a half hour to an hour the wireless signal disappears again . I have seen posts on the net that suggest renaming the wireless channels and changing the channel. Will try these but this seems to me to be a bit of a bandaid - while this may help I'd like to know why this is happening so I can perhaps take other actions to prevent it in the future.