HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

[Oliver111]

Hi! Need help for repair this unit. Problem not typical.
All voltages are present (CPU, GPU, 5v, 3.3v, charging system).
When I try to install Windows it's shutdowns automatically (in 10-15 sec after it recognize flash drive)
3.3V and 5V have a good resistance (kOm's). 5V when work drops to 4.8v, unstable.
I bought 2 laptops with same issue. I think maybe it a typical problem.
Motherboard - DAG3HIMB8C0 REV.C, Quanta G3HI.
Can anybody help? Thanks

[Oliver111]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Two laptops arrived with broken DC PowerJack.
With thermalcamera i saw a heating EC controller, switcher? around usb port, and diode near ec controller.

[natic]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

switcher? around usb port

Hello!
This chip is a "Power distribution switch" for the USB port. It's very likely damaged. Remove it from the board.

and diode near ec controller.

Measure the resistance to ground on the cathode (-) pin of this diode.

[Oliver111]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Hello!
This chip is a "Power distribution switch" for the USB port. It's very likely damaged. Remove it from the board.

Measure the resistance to ground on the cathode (-) pin of this diode.

Thanks for response. I replace usb switch, but no changes.
All resistance kOms (including resistance on cathode, caps around ec). Its heating resister, not diode. It going to 67 pin ITE8987E (AD_TYPE). 5.5V on 67pin, I think its too high.

In this circuit 3 resisters - 100 Om, 8kOm, 2kOm. Heating last resister 2kOm.

Forgot. Voltage in a power button also 5V. It's good? Usually 3.3V.

Thanks for help, sir

[natic]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

I replace usb switch, but no changes.

Does this chip still heats up?
By the way, you can test the board without this chip. It should work normally, except the USB port.

Its heating resister, not diode. It going to 67 pin ITE8987E (AD_TYPE). 5.5V on 67pin, I think its too high.

- Measure the resistance to ground on pin 67 of KBC chip.
- Measure the resistance between the central pin of the DC socket and pin 67 of KBC chip.
- True, this voltage is too high. Measure the voltage to ground on central pin of the DC socket.

[Oliver111]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Does this chip still heats up?
By the way, you can test the board without this chip. It should work normally, except the USB port.

- Measure the resistance to ground on pin 67 of KBC chip.
- Measure the resistance between the central pin of the DC socket and pin 67 of KBC chip.
- True, this voltage is too high. Measure the voltage to ground on central pin of the DC socket.

After replace usb switch don't heating.
resistance between the central pin of the DC socket and pin 67 = 2.09kOm
resistance to ground on pin 67 of KBC chip = 7.91kOm

[natic]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Measure the voltages to ground on pins 11, 12, 26, 74, 127 of KBC chip.

[Oliver111]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Measure the voltages to ground on pins 11, 12, 26, 74, 127 of KBC chip.

Without ITE8987E (firmware saved):
11 - 0V
12 - 0V
26 - 3.3V
74 - 3.3V
127 - 3.3V

Strange voltages on 67 and 71 pins (3.8V - 67 pin; 71 pin - 2.8V).
For test I use original 65W HP genuine adapter.

All resisters in this circuit normally (AD_ID).

[natic]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Is there still 5V on pad 67 on the place of KBC chip (with the KBC chip removed from the board)?

How about that?

Measure the voltage to ground on central pin of the DC socket.

[Oliver111]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Is there still 5V on pad 67 on the place of KBC chip (with the KBC chip removed from the board)?

How about that?

No. Without EC - 3.8V (67 Pin)

19.5V on central pin (AD_ID).

[natic]

Re: HP Pavillion 15-ec2253ng (DAG3HIMB8C0 REV.C)

Measure the resistances between listed pins of power connector in cases a, b, c.
- Between pin 1 and pin 10.
- Between pin 1 and pin 11.
- Between pin 1 and pin 12.

a) DC socket cable disconnected from the motherboard.
b) DC socket cable connected to the motherboard, but disconnected from the power supply.
c) DC socket cable connected to the motherboard + power supply connected, but the power supply disconnected from the wall 220V mains socket.