DIAGNOSIS: Complete power loss. The most common culprit is a tripped thermal fuse on the main control board or a blown main fuse in your home's circuit.
FIX: Check your home's circuit breaker or GFCI outlet first. Unplug the microwave or shut off its dedicated breaker for 60 seconds, then restore power. If it's still dead, the internal thermal fuse has likely blown (often from a clogged grease filter causing overheating). Replacing this fuse requires accessing the control panel—it's a specific repair for this model.
IF THAT DIDN'T WORK: The main control board itself could have failed. A board failure usually follows a power surge or repeated overheating events. You'll need to test for board power with a multimeter or replace the board assembly.
HEADS UP: The thermal fuse is a one-time safety device. If it blows, you must find and fix the cause (usually inadequate ventilation or a clogged filter) before installing a new one, or it will just blow again.