If you have more than one wi fi base station double click on the icon for the wi fi base station that has the amber circle next to it. Fast blinking yellow you are holding down the reset button and are factory resetting this device.

How To Reset Your Airport Base Station Apple Support
Apple wifi router blinking yellow. Open airport utility which is in the utilities folder of your applications folder. The base station has not yet been configured because it is new or the reset switch has been set. The blinking lights on a router are talking to you. Comcast is my internet provider. Launch airport utility to determine why your wi fi base station status light is blinking amber. When the summary window appears double click the amber circle to the right of wi fi base station status to open the status window.
A new firmware update is available for the base. If the status light stays amber in color and blinks after the wi fi base station restarts you may repeat the steps above. To resolve an issue related to base station settings you can either change the setting or tell airport utility to ignore it. You have selected a security configuration that is not recommended. I have had an apple airport router for many years and have been very pleased with it. Click update to apply your changes the wi fi base station will restart.
Its not like the modem light that blinks regularly when we are using the internet but the blinking seems more steady and i don. After it was installed they told me i did not need my apple router as the new box had a built in wireless connection. A apple recommends that you use airport utility 552 for mac airport utility 552 for windows or a newer version of airport utility if one is available. Recently comcast sent everyone a new wireless gateway control box. The status window lists any conditions that require your attention. A persistent flashing amber light indicates that any of the several potential conditions may require your attention.
After the wi fi base station has restarted the status light should be green and not blinking. Ignoring an issue doesnt resolve it but causes the status light to stop flashing for that issue. Apple airport router yellow light blinks will not flash green. If you keep holding down the reset button after about 12 seconds the light will turn solid. A little up front research can prepare you for internet access failures and other computer networking problems. Why does my apple routers light blink yellow occasionally.