Episode Details

Daniel has a 300W GaN charging brick with ten ports, and one of them refuses to charge his pocket speaker. USB-A works fine. USB-C to USB-C just makes the light flash red. Is the speaker damaged? Did the charger fry it? Not even close. This episode unpacks the two completely different philosophies behind USB-A and USB-C power delivery: one is a dumb pipe that hands out five volts unconditionally, the other waits for a proper introduction over the Configuration Channel before it energizes anything. We walk through the resistor-based current tiers, the Power Delivery menu of voltage and current pairings, what PPS actually means, and why a failed handshake produces darkness rather than damage. Along the way we explain why the "better" cable is the one that exposes the problem, why a rapid red flash is a fault code and not a death sentence, and why a fraction of a cent in missing components is the real culprit. Key sources: • USB-IF, USB Power Delivery . — https://www.usb.org/sites/default/files/D2T2-1%20-%20USB%20Power%20Delivery.pdf • rbaron.net, USB Power Delivery for Makers, 2024-06-02 (detailed CC/Rp/Rd, PDO/RDO, PPS, EPR mechanics). — https://rbaron.net/blog/2024/06/02/usb-power-delivery-for-makers • kbytechnologies.com, Debugging USB-PD Negotiation Failures (state machine, failure modes, BadPower, timers). — https://www.kbytechnologies.com/tech-fundamentals/debugging-usb-pd-negotiation-failures Episode 5871 — myweirdprompts.com/n/5871 (permanent short link: myweirdprompts.com/431104)