The STUSB4500 cannot communicate with my I2C

[skyforline]

The STUSB4500 cannot communicate with my I2C bus. The voltages measured on the chip's 1V2 and 2V7 capacitor pins are 3V and 5V, respectively, and VBUS is also 5V. I tried to read the chip ID, but the result was 0, which is obviously incorrect.

The following schematic shows

wiring diagram.

[Didier HERROUIN]

Dear skyforline,
Please share the rest of the schematics, with the MOS-FET on VBUS line and the Discharge circuits.
What is VCC3 voltage value ? 

The voltages you measure on 1V2 and 2V7 are obviously not expected. Can you test another board to check if you have the same behavior ?

Regards,

[skyforline]

VCC3 is 3.3V

The upper left corner is the input terminal, and the right side is the output port .  I have short-circuited the MOSFET, so it can output voltage directly.I am not sure whether it can communicate with the MCU; however, the output voltage is in line with the PDO1 specification.

[Didier HERROUIN]

Dear skyforline,

Shorting the MOS is of course not recommended at all, as you will be exposed to defective chargers which could damage your circuit. The STUSB4500 is immune against defective voltage up to 28V.

In your case, I suspect a board assembly issue or a damaged chipset.

Is VBUS_EN_SNK driven low when a charger is plugged ? 
Can you share a snapshot of I2C signals when the MCU tries to communicate ?
Have you been able to test another board ?

Best regards,