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Can you help me identify this chip? It looks like a SOT23-5 chip, it seems to be part of the USB-C Power Delivery. The laptop doesn’t power up because this chip seems to be part of the negotiation process, because the USB-C PD doesn’t negotiate a higher voltage and is stuck in 5V. I’m struggling to find out what is this chip so I can replace it.

a) I can’t find the motherboard schematics (Huawei Matebook 2020 KLVL-WFH9, motherboard NB2686_MB_V3). The chip seems to be connected to another one in the other side of the board: the RTS5452E, which is a USB-C PD controller, but I can’t find this other chip’s datasheet. If anybody has a laptop with this RTS chip, maybe the circuit could be similar, or a schematic could help to identify the chip.

b) The marking on top of the chip is ABPGB.

c) I tried to make a diagram of the components around this chip, to understand what is its purpose (bare in mind it might be wrong), maybe some of you already know this type of circuit and can tell me what could it be. The pin 1 seems to be connected to USB voltage +5V, the pin 4 to the RTS5452E through a semiconductor D. Any other ideas, suggestions are greatly appreciated, thanks!

location of the IC in the motherboard closer look schematic

UPDATE: I got another motherboard that is working fine and measured the power on sequence on this chip with an oscilloscope, I post the images below. First image is pin 1, when the power usb-c plug is connected, it goes to 5V then after some time it goes to 20V. Pin 2 is GND, pin 3 starts at close to 5V, then increases and then goes back to zero. Pin 4 is at close to 1V during this sequence, pin 5 is close to 5V. I am not sure that these correspond to a voltage detector, anyone can clarify this? Thanks in advance! pin1 pin3 pin4 pin5

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  • \$\begingroup\$ Have you got pins 4 and 5 the right way round? \$\endgroup\$
    – Finbarr
    Commented Apr 4 at 22:41
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    \$\begingroup\$ If all else fails you can sometimes buy junked mombos with only the major parts (BGA parts like CPU, RAM etc.) stripped for $10 or $20, but it helps to be able to deal with Chinese language and shipping. \$\endgroup\$
    – Spehro Pefhany
    Commented Apr 4 at 23:30
  • \$\begingroup\$ @Finbarr you are right, 4 should be 5 and vice-versa. \$\endgroup\$
    – L. Ricardo
    Commented Apr 5 at 7:16
  • \$\begingroup\$ I think it's most likely a LDO regulator with 1-VIN, 2-GND, 3-EN, 4-FB, 5-VOUT. See also this schematic as reference. It shows a RTS5452E and there is a LDO regulator connected to pin 25 for a "dead battery circuit". \$\endgroup\$
    – nanash1
    Commented Apr 8 at 12:07

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Found the below code from here: https://smd.yooneed.one/

Seems like a voltage detector IC might make sense given the application you described. It may be something in that family

enter image description here

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  • \$\begingroup\$ thanks for your reply, I posted some pictures of a oscilloscope measurement for this chip pins working correctly from a different board, the voltage on pin1 goes to 20V, which exceeds the maximum rating for the Voltage detector IC that you mention. Do you think this MAX6307 is still the correct IC? \$\endgroup\$
    – L. Ricardo
    Commented Apr 6 at 20:19

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