Diagnosis
The front control panel's ribbon cable may have become loose or the touch sensors are disabled.
How to Fix It
Unplug the soundbar. Wait 30 seconds. Plug it back in. Immediately press and hold the Volume (-) button on the unit itself for 10 seconds. This reboots the control system.
If That Didn't Work
The control lock may be enabled. On the remote, press and hold the MUTE button for 5+ seconds. This toggles the front panel lock on and off. An icon will show on the display.
Heads Up
If the buttons remain dead after these steps, the internal ribbon cable connecting the control board is faulty. This requires disassembly and professional repair.