DAH98NMB8C0 REV C HF need help

[jhanra]

good day experts!
i have huawei matebook d14
DAH98NMB8C0 REV C HF

the laptop works normaly when using it and charging
the problem is when i shutdown the laptop and not using it, the part in the picture with red circle
becomes so hot you cant even touch it, and it drains the battery quickly
i cant find schematics for this laptop

can someone tell me what is this part so i can replace it

[jhanra]

this is the part
2920u (sot23-5 marking)
when laptop on and charging (normal)
pin 1 vin = 16v battery voltage
pin 2 GND
pin 3 = 0.7v
pin 4 = 0.9v
pin 5 out = 3.3v

when laptop off
pin 1 vin = 16v battery voltage
pin 2 GND
pin 3 = 0v
pin 4 = 1.2v
pin 5 = 2.6v

when laptop is off and charger plugged in (normal)
pin 1 vin = 16v battery voltage
pin 2 GND
pin 3 = 0.7v
pin 4 = 0.9v
pin 5 out = 3.3v

this part is so hot when laptop is off and charger unplugged

i hope someone can help
THANKS

[jhanra]

can i replace it with this?

[mon2]

Do not replace this part till more is known about the original.

The last character of this part looks like a ‘7' ? Pour alcohol onto the top surface to gain clarity of the markings. Can you confirm?

[jhanra]

its not my pic, CTTO, i only edit the video i got from the net, the part marking in mine is 2920u,
forgot to take the picture in mine cause the owner took it and will return it to me when i have the parts

[mon2]

Remove all power. Meter in resistance mode (not diode mode). Measure the resistance to ground of each pin of this SOT23-5 package. The part may be getting hot due to an excessive loading of the output pin. Post each measurement.

[jhanra]

ok i will try that, and post result
thanks for the reply

[mon2]

I think it is part # G2920T11U by GMT but still working on a few leads. More later once at the office. Aliexpress has these.

[jhanra]

resistance
test probe shorted 0.9ohm

test to gnd
pin 1 = 197.8 ohms
pin 2 = gnd
pin 3 = 99.0 ohms
pin 4 = 8.57 kohms
pin 5 = 13.19kohms

the test is no battery connected

[jhanra]

I think it is part # G2920T11U by GMT but still working on a few leads. More later once at the office. Aliexpress has these.

thank you very much, but i cant find this in my location, theres no aliexpress here in the philippine
is there any equivalent to this chip?

[mon2]

Ok - found it. See attached.

From other board pics of a similar model:




This is a HIGH VOLTAGE (for input) low current fixed LDO @ 3v3 output. Should be common to replace with others if the pinout can match.




Datasheet:

[jhanra]

Ok - found it. See attached.

From other board pics of a similar model:




This is a HIGH VOLTAGE (for input) low current fixed LDO @ 3v3 output. Should be common to replace with others if the pinout can match.




Datasheet:

is the ohms reading the same?

by the way thanks for you effort to help me

[mon2]

I do not have this board but a similar one is in my database. The LP*** LDO is rated @ 50 mA but this one from GMT is rated @ 150 mA. You could try it if it is available to you but need to review the pinout functions.



My last post lost the datasheet - it is attached here.

G2920.GMT-1493-220214-0.6.pdf

[jhanra]

I do not have this board but a similar one is in my database. The LP*** LDO is rated @ 50 mA but this one from GMT is rated @ 150 mA. You could try it if it is available to you but need to review the pinout functions.



My last post lost the datasheet - it is attached here.

G2920.GMT-1493-220214-0.6.pdf

thank you for your help, i think my last option is to buy a faulty board here
cause there's no way i can get that part here.

i will post the result as soon as i replace that part

[mon2]

Do you have access to Mouser or Digikey?

AliExpress can deliver the parts to your region?

We can locate a suitable replacement if needed. In the end. This is a fixed 3v3 ldo with an enable pin. The input must be tolerant to a high voltage like the battery or adapter voltage.

[wooddy]

I'm having this problem as well. I don't think the G2920 is bad because pin 8 in the BIOS is shorted to ground. Have you found the problem yet?

[mon2]

With no power, what is the resistance to ground of pin #8 on the bios?

Do you have an adjustable power supply for voltage injection? Do not use higher than 1 volt.