Ask Max: Amber Light Flashing on Apple Time Capsule
I just hooked up a Apple Time Capsule to my Cable Modem, and I want to use it as a wireless router for my house. The amber light keeps flashing, even though everything is set-up and I am connected on my new wireless network. The airport utility is saying that my Apple Time Capsule airport device does not have a valid IP address. What can I do? I want to fix the problem so everything runs like it is supposed to and I have the green light on the Time Capsule instead of the amber flashing light.
It is often necessary to power off both the Cable Modem and the Apple Time Capsule / Airport Base Station to resolve this issue. Make sure that the Cable Modem is connected to the Time Capsule's WAN port. When ready, first turn on the Cable Modem then power up the Time Capsule. After a minute or two, the Time Capsule light should turn green. Once it does, connect to it and make sure you have changed all the passwords from the default setting.
If the simple step of rebooting all relevant devices didn't eliminate the blinking amber light, you might have to make changes to a specific setting. AirPort Utility 5.2 or later should open automatically if you need to troubleshoot your Time Capsule or other Wi-Fi Base Station. If it doesn't, you can access it via Applications > Utilities > AirPort Utility. Once open, locate your Time Capsule and double-click to open its Summary window.
Next, open the Status window by double-clicking on the amber circle next to the Time Capsule Status. Here you will see anything that might need your attention. Put a checkmark in the "Ignore" checkbox beside any option you don't wish to change. A checkmark simply tells the AirPort that you are aware of the issue and you have chosen to ignore it. For example, you may wish to leave your AirPort open without a password so that anyone can join your wireless network.
Click Update to apply your changes, which will reboot Time Capsule.
Now the light should be a static green. If the status light stays amber in color and blinks after the Time Capsule restarts, repeat the above steps. If after a second time it's still amber, then you must go deeper into troubleshooting or perhaps visit an Apple Retail Store or a Licensed Apple Service Provider.
Apple also has a great support article to further troubleshoot.