DIAGNOSIS: Total power failure, no lights. The first place to check isn't the outlet—it's the removable water tank on the back. If it's not seated perfectly, the machine won't get power as a safety feature.
FIX: Take the water tank completely off. Check that the rubber gasket on the bottom of the tank is clean and seated properly. Now, firmly push the tank straight back onto the machine until you hear a distinct click. You should feel it lock into place. Then plug the power cord directly into a wall outlet (not a power strip) and listen for a faint hum or click from the machine.
IF THAT DIDN'T WORK: The thermal fuse inside the machine, which protects against overheating, can blow. This sometimes happens after a descaling cycle or if the machine was run without water. There's no user fix for this; it requires disassembly and a replacement part, so you'd need to contact Nespresso for service.
HEADS UP: The VertuoPlus power supply is built into the base. If the fuse is blown and you're out of warranty, the repair cost is often close to just buying a new machine, which is a real bummer.