Airport Extreme, Mac Cube and proposed Blue Ray /WIFI

Does the non wifi modem give out DHCP addresses?
Can the wifi modem be set up to receive it's IP address from DHCP?
If the answer to both these questions is Yes then that's what to do as a first step. Make sure the wifi modem DHCP service is disabled as it must NOT give out DHCP addresses.
Connect the ethernet port of the non wifi modem to one of the LAN ports of the wifi modem and NOT the DSL/WAN port. The wifi modem is not participating in any DSL connectivity at all so it's DSL light will remain off. The non wifi modem is doing the DSL duty so it's DSL light should be correctly illuminated.

Turn off your security because 10.5 with wifi doesn't play nice with router passwords.

most like the modem is faulty as you can have any number of devices operating together
is it a wifi modem with ethernet
make sure that you add each device by going to the add devices in the control panel

British only say dodgy. so bingo for UK?
reckon is only said by us confederates, rebels.lol well the Arris (SB5101U) moldem is first , its LED happy./

SOUNDS LIKE IT IS BAD DO ME, IF MODEM WORKS
AND ROUTER FAILS THEN ROUTERS IS BAD.
But any router made can be not configured at all.
as in hard reset and fails. so reDO alo that. in the Airport router
AirPort extreme
Apple AirPort Extreme 802.11ac User Manual lets read some pages router
wan jack wired to wan jack on modem, check
the AP status LED light
off means no power.
sold amber means AP is process of starting up;.


SOLD GREEN LED: is good
Flashing Amber (orange/) means.
Your AirPort Extreme can't establish a connection to the network or the Internet,
or is encountering a problem. Use AirPort Utility to get information about what
might cause the status light to flash amber. See "If Your AirPort Extreme Status
Light Flashes Amber" on page 18.

the error above amber blink means the AP can not connect to the ARRIS MODEM. so reset it first. reset it by only unpluging AC power from wall for 5min and put back and wait 15min or until modem shows fully connected, to ISP./
the router is last not first. ISP not down today.
if the modem keeps failing call the ISP..
one can wire connect a PC directly tot the modem and test that way
but I will show a page on that now.

https://red-dot-geek.com/connect-pc-modem-ethernet-cable/


now you learned how to test the modem first and then router.
wired
once wired works both modem and router
we play WIFI H3LL all day long, ask. can do but endless causes to fail, in truth.

Check your connections:

DSL-modem to telephone-jack (or cable-modem to cable-jack).

Ethernet cable from DSL-modem (or from cable-modem) to WAN port on your router.

Ethernet cable from LAN port on router to WAN port on your Airport.

Cut the power to the Airport, and then plug it back in, so that it restarts.

Not sure how helpful this will be, as I'm running a different piece of gear, plus it requires both troubleshooting + ISP assistance.  I had a similar problem with my AirPort Extreme: AirPort Extreme saw the Arris, iBook saw the AirPort Extreme, but no internet connectivity.

1. In my case, I needed to set the AirPort to DHCP in the AirPort Utility application.
2. Power down the AirPort Extreme
3. Power down the Arris. You achieve this by unplugging the Arris *and* removing the back-up battery.
4. Wait a few moments.
5. Insert the battery into the Arris.
6. Plug in the Arris power supply.
7. Wait for the Arris to go through the restart protocol; when all the lights on the front panel are solid green, the start-up is complete.
8. Power up the AirPort Extreme; wait for the front panel light to go solid green.

As I was doing this, I had my ISP on the phone that confirmed complete connectivity of the signal path and ensured that I was online.  While the Arris was powered down, my ISP also sent a "message" to the Arris; I don't know if this was a software update or what.  I completed the AirPort set-uo through the Utility application, the AirPort restarted, and I was online.
Hope this helps.

First of all... Unplug the modem, unplug the Airport (WiFi router) and turn off the Airport connectivity in your MacBook.
After 5 full minutes... Plug in the modem.
Wait 2 full minutes... Plug in the Airport.
Wait 1 full minute... Turn on the Airport connectivity in your MacBook.
After all of that... 
If you're still not back up and running and you're using an Apple Airport, open the Applications folder, open Utilities, open Airport Utility.
If you're using any other type of WiFi router, use the Network Diagnostics button that should show up in the web browser window when you try to go to any website.

Does your mac book has a phone port? You can try that to setup a dial up connection an see if it will work.

well imac G4's don't  have built in airport (wireless internet) included as usual with apple its another item you must buy an airport extreme card  then hook it up to an airport base station another item to buy via wireless internet then hook you airport extreme base station up to your modem via ethernet. whew ok now sync the airport base station to your imac using airport set up application then select your network and type your WEP password and viol internet in about 1 hour if your lucky hope this helped my fingers hurt now LOL.