Airport extreme lost settings and connection

Hi

I have an Airport extreme which has been workingly perfectly since I got it in 2011.

My isp is fiber optic which i connect to through PPPoEand I have had no problem up till now.

I switched off my AE as I would be away and when switched it on again all the orange light was blinking, and congfiguation settings had been lost dns settings etc.

I contacted the isp and got the configuration setting and went through setting it all up again. No joy.

I tried resetting the AE and creating a new network no joy.

I fiddled with DHCP settings. Changed the range. Assigned static ip address to the the MAC address for the AE. No joy.

When I look at the wifi settings in network preferences it has the assigned network ip.

But when it look at the AE utility and look at the status of the network it tells me that i dont have a valid ip address and shows the ip address 0.0.0.1.

I have been fiddling with this for days now. Other message boards have suggested bridge mode and various and sundry things and nothing has worked.

My network cable is now plugged into the Mac and the connection is working fine.

Should i bring the AE to an apple outlet and have them run a diagnostic on it or does someone have a solution?

All suggestions gratefully recieved...