Connecting AirPort Extreme to second AirPort Extreme with Ethernet

Took advice to set up the second AirPort Extreme via a short cable from the first AirPort Extreme.

So, you know that the second AirPort Extreme is set up correctly.

but when I do the same set up from the extended cable I get the orange flashing light

So, because you know that the second AirPort Extreme is working correctly, you now know that the problem is either in the Ethernet cable itself.....(a broken wire somewhere)......or no connection in one of the Ethernet plugs at either end of the cable.

You can get by with a cable like this if you are connecting a computer.....because only 4 connections are required. But....the AirPort Extreme requires all 8 tiny copper contacts on the Ethernet plugs to all be working correctly.

The solution....install new Ethernet plugs at either end of the existing cable.....(this assumes that there are no breaks in the Ethernet cable)......or if possible, install a new Ethernet cable with pre-installed plugs.

When the second AirPort Extreme is working correctly with the long Ethernet cable, you know that the Ethernet cable is now working correctly.