Most wifi issues originate with the Router. Most, not all. Generally, people try and get an inexpensive piece of gear to be their main connection to the outside world, or rely on their broadband provider to give them the equipment. This leads to sub-standard equipment and devices that just dont last long.
Before following the below, write down any port-forwarding settings you have set up on your router.
1. Now, that being said, IF you are comfortable, upgrade your router to latest firmware and then reset it to factory defaults - wiping out all settings.
2. Start from scratch. As if you just bought it.
3. Give it a different name and different passkey.
4. Delete all wifi saved networks from all your devices.
5. Set them up, one by one until you have them all back online.
I go through this with our users all the time at work. Their device works when it is outside their home, but not when it is at home. It generally all comes down to using old and inexpensive equipment.
And stay way away from the combo Modem/Router equipment.
Personally, I do this on a near yearly basis at home, and I have never had issues with the router and my devices. I have had the broadband company replace the modem twice for faulty units.
