DIAGNOSIS Yeah, this one's common. You've likely got a blown thermal fuse on the control board, or a failed UI (User Interface) board. The hum means main power is getting to the unit, but the brains are offline.
FIX Unplug the dishwasher immediately. The fix almost always involves replacing the main control board (also called the UI board). It's behind the front control panel. You'll need to remove the inner door panel to access it. The part number is usually WPY112798 or similar. It's a plug-and-play swap.
IF THAT DIDN'T WORK Before you order the board, check the in-line thermal fuse on the heating element. If it's blown, it can kill power to the controls. You can test it for continuity with a multimeter. Replacing just the fuse is cheaper, but the board is the more frequent failure.
HEADS UP That faint hum is the fill valve possibly trying to open. Don't leave it plugged in like that, as it could lead to a leak if the valve gets stuck open.