Diagnosis
That's a classic compressor start failure. The compressor is trying to start but can't get going, so the overload protector trips after a brief hum. The most common cause on this model is a failed start capacitor.
How to Fix It
Unplug the unit. The start capacitor is a small, usually black cylindrical component mounted near the compressor. You'll need to remove the rear service panel to access it. Visually inspect it for bulging, leaking oil, or a burnt smell. Replacing this capacitor is a standard repair; you need a 15µF, 370VAC capacitor (or the exact match from the old part).
If That Didn't Work
If the new capacitor doesn't fix it, the compressor's internal start components or the relay might be shot. At that point, the repair cost often approaches the price of a new unit.
Heads Up
Capacitors can hold a dangerous charge even when unplugged. If you're not comfortable safely discharging it with an insulated screwdriver, call an appliance repair tech. This isn't a plug-and-play fix for beginners.