Improper configurations and shorts can cause a USB Type-C PD system to constantly reset. The following checks should be used to debug these types of issues:
- Verify that the essential power paths have the correct voltages:
- System_3V3 and System_5V
- System Power: 20 V (or the appropriate configured voltage)
- Probe VBUS, CC1, and CC2 to check for any anomalies. Figure 7-5 shows a successful power contract.
- When there is a short on VBUS, the initial 5 V on VBUS is not present
- Check for a small spike on VBUS during a plug event to verify that the PP_HV or PP_EXT switch is closed and is then opened, once an overcurrent condition is detected.