how to stop blinking yellow on Apple Tower
How to reset Apple Router Tower has a blinking Yellow light ...
iMac, new computer user
If the AirPort appears to be operating normally, but the light is blinking amber, the Apple AirPort router has a message for you.
To find out what it is......
Open AIrPort Utility on your Mac (Finder > Applications > Utilities > AirPort Utility)
Click on the picture of the AirPort router, and a smaller window will appear
If you see an Update button, click it to update the firmware on the AirPort router
Otherwise, look for Status, and click on the small amber dot there for more information and suggestions on what the issue might be and what the fix might be