PD power supply conflicts with serial console?

Follow https://wiki.radxa.com/Rockpi4/dev/serial-console instructions,
connect your RockPI4B to your PC with a TTL 2USB cable.
then plug in the PD power cable(ZMI 65W),
The board does not boot up and LED is not on either.
Without the TTL 2USB plugged, everything works well.

QC power supply works well.
Apple A1718 PD power supply works well.

It’s probably the defect of ZMI 65W power supply.
Will do more test to confirm this.

This is interesting. Does ZMI 65W PD works without USB to TTL connected. Make sure do not connect the red wire of USB to TTL.

Yes, It wors with out USB to TTL connected.
The red wire are not connected.

Tested Lenovo 45W PD adapter, it works well.

Xiaomi 45W(CDQ02ZM it’s produced by ZiMi) also works well.

So it’s more probably the defect of ZIMI 65W PD supply.

1 Like

I have not noticed there is already similar older issue reported so I made this topic Weird behaviour of UART on Rock 4B+

The same issue happens here with two other PD PSUs - RPi5 official 27W and PD451A 45 W (the manufacturer should be Radxa).