HT1218 Problem using a 2nd AE to "Extend" wifi.

Question

I have added a 2nd AE which happily sets up by joining my network. I want to use it to extend the Wi-Fi signal but after changing the wireless setting to "extend  a network" it fails to setup and it shows an ! to the left of the name and the number 1 in a red circle on the right. There are no means to get this Firmware update from that screen. It only asks me if I want to "forget" it.
So I have to "forget" it, power it down and a while after power up it reappears. I click on it, "edit" and change the wireless setting to "join a network". I have done this three times with the same result.
The 1 means the AE needs a Firmware update. On one support page it said "The red number beside any device in Airport Utility indicates that the divice needs a firmware update. Click on the device and hit the update button. The firmware will update and the red number should be gone" I click on it and I only get the "Forget it?" option. In the "Join only..." I only get edit and no option there to update the Firmware.
Do I need the update and if so how to do it?
If that does not fix it how to I make the AE "Extend" my Wi-Fi?
Thanks in anticipation.
Henry
Airport Utilty 6.1
Mac OS Mountian Lion.
AE is A 1392

Answer 1

PROBLEM SOLVED
Using 2 Airport Express to extend the Wi-Fi Range and set-up Airplay.
I recently had problems in doing just that and was helped by a contributor Bob Simmonds. (Thanks Bob for all your time) You might I hope find this helpful.
AE A1264 (1st Gen 802.11a/b/g/Draft N)
AE A1392 (2nd Gen 802.11a/b/g/n simultaneous dual-band)
Airport Utility Version 6.1 (AU)
iMac Mountain Lion
French ADSL or Broadband modem with Wi-Fi
This is what I did…
First, after several attempts to configure the AEs, I did a Factory default on both. (Unplug, use a paperclip to hold in the reset button while you plug in the AE, wait until the light flashes fast, release)
The first AE is connected by ETHERNET CABLE to the ISPs Modem*. This is confirmed in AU by a solid white line between the big world and the AE. A dotted line means it is a Wireless connection.
Open AU and wait until the AE is recognised which can take up to a minute. Click on the AE Image and click on « edit ».  Or look for it in « Other Base Stations »
In the window that opens click on the tab « Base Station »:
Name the Base station and give it a password.
Open the next tab « Internet »
Connect using : DHCP (the rest is automatic)
Open the next tab « Wireless»
Network Mode « Create a Wireless Network »
Name the Wireless Network you wish to create.
Set your security Password
Open the next tab « Network»
Router Mode « Off (Bridge Mode) »
Open the next tab « Airplay» and check box « Enable Airplay »
NEXT
Plug in the second AE, in my case it is the A1392
Wait for it to be recognised. It will appear adjacent to the first AE  with a dotted line (Wireless connection). Click on the second AE’s icon. Click on « edit »
Open the tab « Base Station »
Name it and set a password (same for both in my case)
Open the next tab « Internet »
Connect using : DHCP (the rest is automatic)
Open the tab « Wireless»
Network Mode « Extend a Wireless Network »
Choose the Wireless Network just created
Set your security Password
The contents Under the tab « Network » will be greyed out.
Open the next tab « Airplay» and check box « Enable Airplay »
If the AEs are shown with a steady green spot to their left all should be OK
TEST  THEM
If either of the AEs are shown with a blinking green spot to their left or an exclamation mark and/or a number in a red circle to the right then there is a problem. The number indicates the number of problems. You may see a short list of them when you click on the AE icon.
If there is a problem and the AE Icon only gives you the option to « forget » then click on « forget » unplug thje AE and replug it in again to start over. I had this a few time and so resorted to a Factory default reset.
I also had aproblem using the ETHERNET CABLE the first caused problems during setup. Changed it and it seemed better.
* If you want full use of the I simultaneous dual-band feature of the new AE then make it the main base station. I
If anyone sees any errors please tell me.