router looks okay but can't connect to wireless

Are you sure that you're entering the Wi-Fi access passphrase exactly as printed on the label (or whatever you've changed it to)?

I'd unplug the 5031 from power, wait 30 seconds, and plug it back in.

If that doesn't fix it, then I'd change the router's SSID and passphrase to something else.  After you do that, you can change it back to the original if you'd like.  See if that does it.  If not...

I'd unplug the 5031, hold the button on the back of the 5031 and plug it back in while holding the button for 10 seconds.  After it boots back up, you'll have to re-enter any changes you've made to the settings (custom port forwards, etc.).  See if that fixes it.  If not, report back here.

We've tried all the suggestions and none have worked.  What's the next step?

No one has responded to this.  We haven't had access to the wireless for three days now.  We've had the router for several years.  What's the next step/

Sorry we dropped you here.  I'd say at this point you'll have to contact AT&T.  You can either call them at 800-288-2020 or you could click this U-verse Customer Service link to send a Private Message (PM) to the AT&T customer service team to help you resolve your request. You can expect a reply via return PM (the blue envelope in the upper right hand corner of this site, next to your name and avatar) in a business day or three.

This is a group of U-verse service specialists who are knowledgeable about U-verse and will stay with your problem until the end (instead of forgetting about it when the phone hits the cradle). Speed things up by including in your private message (only) your name, Billing Account Number, and the best time and way to reach you.