Sound will not come out of sound bar

Does the soundbar have power?  I mean is it turned on?  If so, make sure you did not "mute" the Uverse receiver.  Check to make sure the AT&T receiver volume is turned all the way up.

You can also go to "menu" and scroll all the way to the right to "help" then select trouble shoot and resolve.  After that go to sound and select your issue.  See if it will walkk your thru the problem so you can get it corrected.

There are a lot of possibilities.

Probably the only fail point for connections is if you are connected optical & it is not seated right there will be no sound. Your description is confusing. Most soundbars will have one or two connections, therefore, you do not connect all your components to it individually. You connect through the TV.

It sounds like you only have no sound from u-verse. If the u-verse is connected to the sound bar direct then it could be a bad connection or the STB is muted (as Beebee suggests). Check for that by seeing if the TV sound works when you turn on the speakers.

You turn OFF the TV speakers when you want to use the sound bar. If your connection goes through the TV, the sound bar may not work when the TV is muted.

Or, it may not work on surround sound trying to pass through the TV. All TVs work differently & there are differences in how the components are connected.

To make suggestions we really need to know your model numbers and exactly how your devices are connected.

What's the make and model of your sound bar? (this can help us if you you don't solve it quickly)

Is the sound bar have the correct source for it to play sound? (ie, the input is U-verse, not your DVD player)

How is the sound abr connected to your STB?

The sound Bar is a Samsung Crystal Surround Air Track HW-E550.  I forgot to explain that my TV, Sound Bar where working perfectly.  What happened is my AT&T uverse remote broke & they sent me a Point Anywhere Remote & while trying to program this new remote to control all my equipment that is when I lost sound from the sound bar. 

I did do a factory re-set on the AT&T remote & was able to get sound from the TV so I can at least watch TV with sound but my sound bar is still not working.

You are saying your u-verse remote can not control the soundbar? You can hear the sound through the soundbar if you use the soundbar remote?

When you program the u-verse remote for a TV, the default is that the vol buttons ALWAYS CONTROL the TV.

To move control to the SB first requires a code to be applied to the AUX button. Sounds like you once had a code that others cannot find.

Then you have to change the vol control to either ALWAYS AUX or follow the mode button.

Then add the AUX to the auto power list.

I just remembered, I think someone reported using TV codes for the soundbar. Try it on the TV button. Id you find a code, you can change the AUX button to be another TV button because the code ranges are different for TV & AUX.