Some technicians expect 5V on both ends, but on certain models, the side connected to the Hydra PD (Power Delivery) may show a much lower voltage (around ) depending on the state of the circuit. Symptoms of Failure: Phone does not react to the charger.
Economics & Finance Full Form: Purchasing Power
: Modern fast-charging standards like USB Power Delivery (PD) require devices to handle fluctuating voltages—from standard 5V up to 20V or higher. The "VAR" in this rail's name highlights its capacity to accommodate these shifting levels safely. pp-var-usb-rvp
Understanding the role of this rail leads directly to recognizing the symptoms of its failure. A malfunctioning PP_VAR_USB_RVP circuit can cause a wide range of issues:
: When testing the line using a multimeter in Diode Mode , the meter will read 0.000V or sound a continuous continuity beep, indicating a direct short. Some technicians expect 5V on both ends, but
Technicians often encounter failures on the line. Because this line is "hot" (active) the moment a charger is connected, it is susceptible to electrical stress. 1. Short to Ground
When troubleshooting on a logic board, technicians typically look for: The "VAR" in this rail's name highlights its
The charging control IC (e.g., U9300 Hydra) validates this voltage via signals like CHARGER_VBUS_VALID .
: Power Positive. This indicates a power supply line carrying positive voltage, as opposed to a ground (GND) or a logic communication line.