Samsung Galaxy Book 3 NP750QFG - Doesn't charge on 2nd port

[tommy97]

Hi,

I have a Samsung Galaxy Book 3 NP750QFG that charges only on the first USB-C port, and only when the cable is plugged in one way. On the second port, it occasionally shows 5V / 0.80A. I’ve already replaced both charging ports, but the issue remains.

Where should I look next, and what could be causing this problem?

[mon2]

Best tool for this is the Qianli Tail tester = ~$20 USD from Mobile Sentrix. You now have a branch in the UK for this company. Suggest to purchase one as it can quickly review all USB-C interface lines.

Based on the shared information, suspecting that an ESD TVS diode on the CCx line may be shorted from a previous ESD event. Remove all power. Meter in resistance mode. Measure the resistance to ground of the CCx pins on the USB-C connector / motherboard traces. If the resistance is low, the TVS diode has triggered and needs to be replaced or at least removed off the board.

[tommy97]

That's correct cc2 and vbus is missing. I've looked at the mobo however lines aren't visible