Q: Airport extreme 802.11n won't connect to internet

After returning from vacation, having shut down all power to electronic devices, I returned to have an issue with airport extreme. It appears to boot properly and diagnostics have it running through first 4 items until it hits internet. It remains red and won't connect. I am using a cable modem. I have reset the cable modem numerous times with and without airport connected. No change. I reset airport to default setting and created a new wifi network. Again, no change.  I also attempted a firmware update. "Error occurred while attempting firmware update" and it never could update. I have contacted cable provider and connection is good. Modem works properly using ethernet connection. I have been able to connect wirelessly to unprotected wifi connections, just not my own network, old or new. I am at a loss. Did my airport die?

thanks,