DAG7ELMBAC0 motherboard windows crashes.

[Francisco.s]

Hello everyone, have a HP laptop with DAG7ELMBAC0 motherboard that crashes when booting windows.
With a pen-drive with Linux or hiren's is the same, only with ms-dos programs run without problems.
It passes all ms-dos memory tests, and also all Pccheck 6.1 tests. (some tests not run properly because are not designed for new CPU)
Same with other bios and other ddr4 module.

I have disconnected the vcore rails from GPU in order to test with only internal Intel graphics, to no avail.

In the past I've had the same problem, but due to corrosion near kbc chip, and solved cleaning carefully.

Do you now how to test it in ms-dos with a program that stress the CPU?

Thanks jn advance,

[tony.knors@live.com]

Hi, hope you have solved your issue ? I have the same laptop/mainboard and I am desperate for high resolution pictures of the mainboard front & back because I have a loose 3 PIN SMD component (probably voltage regulator) and looking for where it is missing. Could you provide me with some pictures please ? Big thanks !

[Francisco.s]

Hi, hope you have solved your issue ? I have the same laptop/mainboard and I am desperate for high resolution pictures of the mainboard front & back because I have a loose 3 PIN SMD component (probably voltage regulator) and looking for where it is missing. Could you provide me with some pictures please ? Big thanks !

Yes, I already have the board, still working with the crashes issue,

Please take a photo from your board where the 3 pin smd is located and I will tray to find out which component is it.

[tony.knors@live.com]

That's the issue .. I have the part but not the location on the PCB ! The part is a 3 PIN SMD with reference X32A. I added a picture.

[Francisco.s]

I think the problem with this board is the cpu vcore, being a little higher. There are two phases circuit in the cpu vcore, having 1.6 volts at the output of that circuit.

With the oscilloscope I can measure about 400khz pulses at the input of both coils, but sometimes one of phases doesn't work. (pulses are missing randomly in that phase)

The chip that controls the mosfets of that circuit is a Richtek RT3612EB.

I have downloaded the datasheet of that chip, but it is a nightmare the way it works. I will tray to locate a similar board with this Richtek chip that help me to solve the issue.

In the mean time if somebody have any idea that could help, it will be great.

[Francisco.s]

[QUOTE=tony.knors@live.com;n3219606]That's the issue .. I have the part but not the location on the PCB ! The part is a 3 PIN SMD with reference X32A. I added a picture./QUOTE]

It seems a little mosfet, but could be a bipolar transistor or a double diode. I will tray to locate it in the board and send you a photo of the area it is located.

[Francisco.s]

Here you have a photo where the 3 pins smd is located. Seems that it is the LID sensor chip, so the laptop has to work without it.

The central pin is connected to gnd, and one of the other is feed wirh 3,3 volts.

Hope it helps you.

[mon2]

Datasheet for this Hall effect sensor can be found here:

https://pdf.dzsc.com/2000626/200006260852246695.pdf

[tony.knors@live.com]

Thank you so much but are you sure we have the same mainboard as I cannot seem to locate this part of the PCB ?

[Francisco.s]

Thank you so much but are you sure we have the same mainboard as I cannot seem to locate this part of the PCB ?

Seems to be the same board, can not see the revision in your board. Look near the hdmi connector, it is located very close to it.

[tony.knors@live.com]

Hi Francisco ! Really appreciate your efforts to help me out ! If you need my help, let me know ! This is a picture of the area around the HDMI connector. The board revision is : MODEL G7EL - DAG7ELMBAC0 REV: C

[tony.knors@live.com]

UPDATE !!!! I found it ! It was on the other side of the PCB and as it was still mounted in the laptop I didn't see it ! THANK YOU SO MUCH Francisco !!!!!

[Francisco.s]

I'm glad you solve the problem.

[Francisco.s]

If you need my help, let me know !

It will be great if you can post the vcore voltage in your board. Also the diode mode readings of the pins of RT3612EB.

[tony.knors@live.com]

Hi Francisco, no problem but you will have to give me precise instructions what/where to measure. Also please note that currently my mainboard is not functional. It powers up but nothing on screen. I suspect the BIOS is corrupt and I am waiting on a new BIOS chip I ordered in Taiwan.

[Francisco.s]

Francisco, no problem but you will have to give me precise instructions what/where to measure. Also please note that currently my mainboard is not functional. It powers up but nothing on screen. I suspect the BIOS is corrupt and I am waiting on a new BIOS chip I ordered in Taiwan.

Hi tony, if your bios is corrupted, you don't need to replace the bios chip.

It only needs to be re-program with new data from Badcaps or HP website.

I will tell you how to take the measures and the pines of the Richtek RT3612EB chip.

[tony.knors@live.com]

I'm used to flashing chips like Arduino compatible, ESPressif, Atmel ... but never flashed a BIOS yet and not sure if I have the right tools for it.

[tony.knors@live.com]

Just ordered the tools ! :-)

[Francisco.s]

'm used to flashing chips like Arduino compatible, ESPressif, Atmel ... but never flashed a BIOS yet and not sure if I have the right tools for it.

Hi tony, I know some people use a Raspberry Pi with the flasrom program for flashing bios, but the cheapest way is to buy a CH341A + SOIC8 clip + adapter.

I will tell you how to take the measures and the pines of the Richtek RT3612EB chip.

You should use a multi-meter in diode scale with red probe to gnd and black probe to the pins of the chip.

Most of the pins readings will be in the range of .500 to .600.

Only pins from 6 to 22 are relevant for me. I've attached a screenshot of a board-view from other model for reference.


This chip is located in the same side of the board as the 3 pins smd.

[tony.knors@live.com]

Hi, sorry for the delay as I was out of home for a few days. Can you make a picture of that chip on the board ? Can you explain diode mode, you mean like for testing a diode ?