My Apple box has a light that has always been green. Now it is amber and my YFI doesn't work in my house.

It's possible the airport is bad, but more likely it's not. Try this...

Reboot your modem first and wait until it comes to a steady state, then reboot your router.

If necessary use System Preferences > Network > Assist me

Is it a solid or flashing amber LED status light? If it is solid, then there may be something amiss with the base station's power supply.

However, a persistent, flashing amber light indicates that any of the several potential conditions may require your attention:

• The base station has not yet been configured because it is new, or the reset switch has been set.
• You have selected a security configuration that is not recommended.
• A new firmware update is available for the base station.
• One of several other conditions, such as a disconnected Ethernet cable or invalid IP address has been detected.

(ref: AirPort base stations: About AirPort base station status lights (LED))

To find out why your base station's status LED is flashing amber:

• Open AirPort Utility
• Click on the AirPort base station
• Look for a Status setting in the small window that appears. Note: Status only appears if there is an issue or notification.
• Click on the small amber dot there and another window will open to explain what the "issue" might be.