None of my Android devices will connect to wifi

Neither my Samsung Galaxy Note Edge, Amazon Kindle Fire HD 8 5th Gen nor my Asus Eee Pad Transformer TF101 will now connect to home wifi the past 2 months. I have tried every conceivable iteration of hints and tips but nothing works. This is SO frustrating! My Windows Dell Notebook connects and hus' devices connect. I have tried everything. Change this setting, reboot this device, turn off that router, change the dshc, remove location, deny google, etc and so forth. Is there an app to install? Do I hire some kid to fix it? What?

So no one has ever heard of this issue?

Is this a new development, have you been able to connect in the past?
Does your router have a Firewall feature and if it does have you allowed the devices to have access?
I probably should have asked this first, does the router support the bands that the devices need?

GRIM