Completely dead: no lights, no sounds
When nothing at all happens, the question is whether power is reaching the machine. A tripped breaker, a switched-off outlet or a partly unplugged cord account for a fair share of these calls, and all are safe to check.
If the outlet is confirmed live and the machine is still completely unresponsive, the fault is inside — the inlet wiring, a thermal device or the control. That is a technician's job; do not open the cabinet.