On my phone and on my computer I can’t access the net, although both indicate that I have WiFi. If I turn WiFi off, on my phone I can access the net.
Ok.. your phone is working over 4G connection.
My router says it’s on.
Sorry but is your router the Time Capsule (TC) or some ISP supplied router for example?
What make and model is main router? (assuming not the TC)
Does it have wifi and if so connect to that and see if internet is working?
If it is only ethernet single port.. then it is a modem but can still be tested if your computer has ethernet. For normal cable modem you need to power off the modem for 15min or so then power up again with only the computer connected.
The tiny yellow light on my apple time tower thing is flashing. It appears to be hooked up.
Open airport utility on a computer or phone .. iOS version can be downloaded.
A yellow blinking light tells us something is unhappy.. not details which we need.
Please tell us what is showing as the error when you click the icon of the TC in airport utility. A number of errors will show up. A screenshot is helpful but don't worry about it now.
Quick fixes.
1 Restart everything in order.
Shut down everything .. including main modem if you have that. Wait 15min.
Power up modem.. wait 2min
Power up TC.. wait 2min
Power up computer and phone wifi.
2 Reset the TC using the reset button located near the power plug for 10sec.
Redo the setup as the TC does occasionally fail and load wrong setup. The airport utility will lead you through the setup.
Use short names, no spaces and pure alphanumerics. NOT apple recommended names.
Password same rules but longer.. 8-20+ characters.