No power, shutdown on startup, and failure to reach the dashboard
Xbox consoles that show no response to the power button, power on briefly and immediately shut down, or begin startup and then fail before reaching the dashboard cover a range of fault types. Power supply issues — internal on Series X|S and Xbox One X, external brick on Xbox One and One S — are the first assessment point. Overheating from dust accumulation or degraded thermal paste can cause the console to shut down during the startup sequence before the fan has reached operating speed. Board-level faults are less common but do occur and require bench diagnosis to confirm.

