First of all we need to verify that all the relevant cables are connected to the router. Second, we should ensure that your Wi-Fi is enabled on the mentioned devices.
It is possible that although your router may be on, it is not sending out any signal. This could be caused by a loose connection on the antenna or that some settings have been changed. To verify this you can log onto your router using you PC and the IP address on the back or underneath the device.
From there you can have a look at the settings.