Dead Board: Tracking the Power Rail

No power means start at the wall

When a console is completely dead, the fault is almost always in the power path: fuse, input rail, regulator stage or a shorted downstream chip. Work in a strict order and you will find it every time.

The no-power checklist

1. Verify the supply and cable are good at the port
2. Continuity across the main fuse / filter
3. Measure the input rail for a short before applying power
4. Apply bench power at current limit and watch for the throttle
5. Chase the regulator output rails in order
6. Isolate the failing rail with resistance divides, then repair

Know your rails

Consoles have a fixed boot sequence: standby rail, main 5V, then 1V-ish core. A rail missing at step three explains a board that lights nothing.

Warning: The power supply area of modern consoles can hold charge after unplugging - discharge the mains caps before probing.