Wifi issues

Your can tell your Mac to Forget the WiFi network that the Time Capsule is providing, but the Time Capsule will continue to broadcast a WiFi signal, which you may not need.

if you don't plan to use the Time Capsule WiFi network at all, it would make more sense to turn off the WiFi function on the Time Capsule to avoid having an extra WiFi signal floating around to make things more complicated.

If you decide to turn off the WiFi on the Time Capsule, log onto the router's WiFi network.....(you are probably already connected to it)......and follow the same instructions as above using AirPort Utility except click on the Wireless tab at the top of the window and change the setting for Network Mode from "Create a wireless network" to "Off"

Then click Update at the lower right of the window to save the new setting and let the Time Capsule restart again.

Since you currently can log onto the Time Capsule WiFi network to back up, you should also be able to use AirPort Utility on your Mac to check some settings on the Time Capsule.

Log onto the Time Capsule WiFi network

Open AirPort Utility on your Mac, located as follows Finder > Applications > Utilities > AirPort Utility

Click on the picture of the Time Capsule

Click Edit in the smaller window that appears

Click the Network tab at the top of the next window

Check to locate the current setting for Router Mode.

It will very likely be either DHCP and NAT.......or........Off (Bridge Mode)

Which setting......DHCP and NAT......or......Off (Bridge Mode) do you see?

We need to ask some questions to figure out how things are connected now and how they need to be connected to get everything working on the same network.

If they are, you will be able to back up to the Time Capsule using either the router's WiFi network.....or......the Time Capsule's wireless network without having to log off of one network and log onto the other.

We can't ask all the questions at once because each question can result in different answers and it is your answer that will tell us what question(s) to ask next. So, you'll need to be patient if you want to work through this because there will be no quick fixes.

The first question.......Is the Time Capsule currently connected to your main router using a wired Ethernet cable connection?

The only way to connect the Time Capsule to your router is by using an Ethernet cable. No other type of connection will work.

The Ethernet cable needs to connect from one of the LAN <--> Ethernet ports.......(there are usually 4 of them on most routers, use any one that you wish)........ to the WAN "O" (circle of dots) port on the Time Capsule.

Post back to confirm that this is the case and we will proceed. We will assume........(not a smart thing to do)........that you have a good Ethernet cable.

Change the Router Mode setting to Off (Bridge Mode)

Click Update at the lower right of the window to store the new setting and restart the Time Capsule

After a minute or so, there should be a green light on the Time Capsule

Power off the Time Capsule by pulling the power cord from the back of the device, or by pulling the AC cord from the wall socket

Power off your router in the same way unless it has a power switch

Restart your Mac

Power up the router and let it run for a minute or two

Power up the Time Capsule and let it run for a minute or two

Log onto the router's WiFi network and try to run a backup

Note.......This may or may not work at this point depending on how some other settings are configured

If the backup occurs over the router's WiFi network, you are all set

If it doesn't, wait for an error message to appear and post back with the exact text of the message

Nice work! Happy that things are working for you now.