We have an issue in one of our designs where the CYPD3125 is not communicating with any host device. We had it working at one point with the power negotiation functioning as expected with CY4531 evaluation kit. After one good power up the CY4531 evaluation kit no longer functioned as expected. It will not power up our device or other off the shelf USBC products we verified work with other supplies. Even the USB flash demo will no longer work on the CY4531. Since then we have tried using a separate USBC power supply device. We have verified this supply works with other, off the shelf USBC devices. But our board will not power on.
All we see with the packet analyzer when attaching our board is the source sending out SOURCE_CAP messages. Our board's CCG3 never seems to respond to these. It also will inconsistently draw the current limit of the supply, 3A. Every few packets in the CY4500 analyzer output shows -3A on VBUS and no current otherwise.
We tried reworking the board to replace the CYPD3125 and still see the issue. We also tried plugging the board in while there was no CCG3 device on it and did not see any current draw with the analyzer, so we don't think there is a short on the board itself (unless there is a reason for the analyzer readout to not function with one side of the connection not having a CCG3). The firmware we are using was functional when the power negotiation worked once so we don't think that is a cause of failure. Plus the firmware does work on our other designs.
Any insight or support to help track down the problem would be greatly appreciated.
