I have an Apple Time Capsule 802.11n (3rd Gen) running firmware 7.5.2.
The amber light was blinking, and AirPort Utility shows that I need to do a firmware upgrade to 7.6.
However, when I try to do so, it fails with "error occurred".
Not a lot to go on, and I've checked the Apple support site. The readme for the update says I should use AirPort Utility 5.5.3., which is the version I am using.