USB-C PD basics: no power, 5 V only, or flaky bricks

Bench notes for USB-C Power Delivery faults on laptops (NLCRC original wording). What “PD” usually means here - CC1/CC2 negotiate a contract; the brick may stay at 5 V if CC is open, shorted, or the PD controller never answers. - VBUS can be present while the system still refuses to boot if the sink path / e-marker / controller rail is wrong. Checks - Try a known-good 65–100 W PD brick and a known-good cable (e-marker matters on many boards). - Inspect the USB-C receptacle for bent shields and burnt CC pins. - Measure VBUS and the PD controller VDD; look for shorted MOSFETs on the VBUS path. Scope / protocol - A PD analyzer helps when the brick “pulses” or drops under load. Without one, swap cable/brick/port first. Post board PN, which ports fail, whether barrel jack (if any) still works, and measured VBUS.