Receiving time capsule Keychain error -25293
Mavericks as always..
When you factory reset the TC, did you use all short names.. no spaces and pure alphanumeric for everything.. TC name and wireless name/s. This is important. Do not change the TC password from default, ie public.. if you need to type in a new password keep the old password.. ie public.
Delete the current Time Machine setup and start over.
See A4 here.
Manually mount the TC.. in Finder use Go>Connect to server..
And when requested for the password type that in.
If it still gives you a password error then I am not sure where to proceed next.. but my inclination would be a clean install of the OS.