Diagnosis
When only the power light is on and the control panel is otherwise unresponsive, it usually points to a main control board failure or a loose internal connection. It's less often the user interface panel itself on these models.
How to Fix It
Unplug the washer from the wall for a full 5 minutes. This performs a hard reset on the control board. After plugging back in, press and hold the Power button for 5 seconds. If the panel springs to life, it was a temporary glitch. If not, the next step is checking internal wiring.
If That Didn't Work
You'll need to access the main control board (behind the back panel). Before you do, check that the washer is on a dedicated circuit and your home outlet is providing power. A voltage drop can cause this. If power is good, a loose wire harness connection on the control board is possible, but more likely the board itself (part # 6322ER2004A is common) has failed.
Heads Up
If you open the control panel, capacitor(s) on the board can hold a charge even when unplugged. Don't touch the board components unless you know what you're doing. This is often a "call a pro" diagnosis.