DIAGNOSIS This points to a power supply issue, either a loose internal connection or moisture on the control board. It's rarely a full board failure.
FIX First, rule out external power. Unplug the machine and plug it into a different, known-good wall outlet. Avoid using a smart plug or timer for this test. If the display stabilizes, the original outlet was the problem. If it still flickers, unplug it and let the machine sit dry for 24 hours. Sometimes steam or condensation finds its way into the electronics and needs time to evaporate.
IF THAT DIDN'T WORK There's a hard reset procedure. Unplug the machine. Hold down the Power button for 30 seconds while it's unplugged. Then, plug it back in while still holding the button for another 10 seconds. This can clear a glitched state in the controller.
HEADS UP Never pour water or cleaning solutions directly over the button panel or display. Always wipe controls with a damp cloth, not a soaked one.