Help to identify component HUAWEI MATEBOOK 15- USB-C POWER - Looping from 5V to 0.9V - IC U20 90º celsius HOT!!

[matheus30]

First of all, thank you all for the help you provide in this forum.

HUAWEI Matebook D15 Laptop - Mod: BOB-WAH9 - Motherboard: DAH98MMB8D0 REV D

Can anyone help me locate the manufacturer of this IC? and tell me if the IC U20 is really the problem.

When looking at the board with the thermal camera, the integrated U20 is set to 90-95 degrees Celsius and the USB-C tester that I have between the charger and the laptop, oscillates between 5V and when it reaches 95º, it drops to 0.9V... .and so on in loop mode.

There are no apparent shorts in the capacitors or coils, and if we apply cold with an air compressor to the U20 chip, the loop stops and the 5V goes to 20V
(USB-C switching), curiously, voltage only enters when the USB-C cable is on one side, if we turn it, no voltage enters the pins of the USB-C connector. Tested with 3 different chargers, and it does the same. The USB-C connector looks ok at microscope.(external and internal pins)

Measuring with the working side of the USB-C cable, Pins 4-5-14-15 give 5V, and drop to 0.9V when the chip is turned to 95º...and the loop begins.

Attached detailed photographs of the motherboard part.

The integrated U20, on the front of the chip it says 4GD and a Chinese logo very small, looking with the microscope from the side, it has 3x3 solder balls.

There is no schematic or boarview available anywhere.

Thanks a lot!!

[mon2]

Post the best picture you can take of this WLCSP9 packaged device.

[matheus30]

Here they are, U20 zoomed at max.

[mon2]

What is nearby? Usb connector? The limited boardview balls seem to hint this to be a load switch.

[matheus30]

I unsoldered it to take the photo below, and we put new tin on it and assembled it. And it does the same.
The chip is part of the current input circuit of the single USB-C port, I have also changed the previous mosfet (EMB20P03), and nothing.

[mon2]

Can you trace the wiring from the USB-C port pads to this device? This may be a low capacitance ESD suppressor that has taken a hit. Such devices use a flow-through pinout and will not impact the USB operation as long as this device is not defective but the ESD protection is then lost.

[matheus30]

https://es.aliexpress.com/item/1005003719441982.html

https://www.mouser.es/datasheet/2/30..._D-2314121.pdf

Can this be?

[mon2]

Review the pinout from the full datasheet.

Check the resistance from the I2C lines (SCL / SDA) of this device's PCB pads to the VCC rail. What is the measurement of each? This is to confirm that the pull-up resistors are present on the board for the I2C lines. The readings should be close to each other.

FUSB302B - FUSB302B Programmable USB Type‐C Controller w/PD (onsemi.com)

[matheus30]

Thank you Mon!! I try it.

[matheus30]

I was wrong...

FUSB302B, Don't works

I need Ground in B3 and VBUS in A1, I try it with :

NX20P0477

https://www.mouser.es/ProductDetail/...jptM09NA%3D%3D

[matheus30]

I found a user with the same problem, and he find it...is the same IC

https://www.badcaps.net/forum/troubl...h98ambad0-dead

The shit IC: https://www.richtek.com/assets/produ...DS1711H-04.pdf

[matheus30]

Solved, works!

[Kalman27]

Hi there,

I have a similar problem.

The motherboard only takes 5v, it doesn't get hot anywhere.

Do you think that same chip failed?

If not, any idea what can be a problem, there is no short on the motherboard.

Thank you

[mon2]

Perhaps. Meter in diode mode. Red meter probe to ground, yes ground.

Black meter probe to pin to test.

Test the CC1 and also CC2 pins on the usb c connector. Post each measurement.

[Kalman27]

I'm new, so not sure if I measure the right pins. I can't find a board view or schematic.

I believe both 0.634v.

Thank you

[mon2]

These are good CCx measurements for diode mode. Note that this PD controller is a slave device and its firmware is controlled by another higher up controller (AP / CPU or EC controller). Those parts must also be working for this PD controller to function. At this time, do not suspect this PD controller to be defective but share close up pics of this controller in question. Checking for defects.

[Kalman27]

Thank you.

I understand now. I found some corrosion on the board and also a component that gets slightly warm, but it is unclear to me how as no current goes in.
I believe this is the USB-C controller -



The area where the corrosion was, and the chip which gets warm (30C) -



Thank you

[mon2]

30C is not considered to be a high temp. Any regulator that converts a high voltage to a low voltage will raise the device temp in the process. Higher the efficiency of the regulator, the lower the temp rise over ambient.

Have you attempted to reverse plug into the usb type C connector to test the other side of the dual blade connector? If you use one side, then CC1 pin is tested. If the other side, CC2 pin is tested. If you have more than one USB C connector onboard - test each in the same way.

Do any of the port permutations offer 20v or a higher current draw?

[Kalman27]

Thank you.

There is only one USB type C connector and both ways have the same 5v and no current.

[TechgeekSVK]

Thank you.

There is only one USB type C connector and both ways have the same 5v and no current.

Have you repaired it? I have also this problem. Thanks in advance.