Apple Time Capsule will not start -up, light stays amber
Does it appear at all in your list of wifi access points on any of your devices? If so, try to connect to it and see if there's anything mentioned in the Air Port Utility app.

If it doesn't, I managed to find this discussion on the Apple Discussions forum regarding Time Capsules being stuck on the amber light at startup. The possible problems suggested by those forum-goers include:


Failing power supply
Failing HDD


If your Time Capsule is within warranty, it'd be worth it to take it in and have them look at it. Unless it's a failing HDD, however, it's not looking like there's a lot in the way of DIY repairs for the device.