Q: AP Time Capsule Intermittantly Not Connecting

I'm betting the culprit is Yosemite. I too have started to have this issue after upgrading my Macs to Yosemite. My 6th gen Time Capsule would mysteriously go off-line after about 24 hrs of operation. There are a number of "solutions" posted here in the Apple Support Communities, but no real solution as of yet.

One thing that I found that helped extend the amount of time between resets to about a week is that I used a script at startup that mounted my Time Capsule's internal HDD. It was written to use the Apple native file sharing protocol AFP. I switched that to SMB. But, again, the issue reappeared after about a week.

The script I mentioned was written in AppleScript and looks like the following:

try

     mount volume "smb://<fileserver name>/<fileserver sharename>" as user name <"base station administrator name"> with password <"shared disk password">

end try

For fileserver name you would enter either the base station name or IP address. For filesever sharename, you would enter the shared disk name.

As an example, using TC as the base station name, Disk_Share as the shared disk name, Administer as the base station's administrator's name, and mydrivepassword as the shared disk's password, the script would look like the following:

mount volume "smb://TC.local/Disk_Share" as user name "Administrator" with password "mydrivepassword"

Export the script with a File Format of: Script. If you want the script to run at startup, just add this script to the user account on your Mac.