HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

[Dakay]

So I’ve been looking at this motherboard for a few days now. It’s an HP Omen 17” and the motherboard number is DAG3CMB1CH0. There are no schematics for this. I have it hooked up to my power supply, 19.5V, but isn’t drawing any amps. Im completely new to working on these gaming laptops. Does anyone have any idea or direction on what could be the problem?

It appears that power isn’t getting past the first two mosfets (with the exception of a current sensor near ssd which reads 18.5V, and a Capacitor that reads 6.0V) and everything looks shorted to ground, but i can’t figure out which component needs to be replaced.

Thank you all for your time and consideration!

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Attaching pictures of the motherboard

[caspian]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

How much resistance is measured before and after the two Mosfets?

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

How much resistance is measured before and after the two Mosfets?

Thanks for the reply. I can get that info for you later today. I did take some components off near the SSD, and it seemed to increase the volts on the supply of the first two mosfets from 0v to .9v. Whatever the issue is, it seems to be effecting the entire board, and i dont believe it’s the first two mosfets. Would the super i/o cause the entire board to short out? How would i test that?

[caspian]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Super IO is not likely to make 19v shorted. Remove all power from the laptop and focus on measuring resistance.

[Weelcup]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Thanks for the reply. I can get that info for you later today. I did take some components off near the SSD, and it seemed to increase the volts on the supply of the first two mosfets from 0v to .9v. Whatever the issue is, it seems to be effecting the entire board, and i dont believe it's the first two mosfets. Would the super i/o cause the entire board to short out? How would i test that?

The short could be anyware. However, as per experiance i would suspect a capacitor is shorted before i suspect a mosfet. Although both of them are the main causes of such short...

You mentioned you have a 0.9v on the shorted side. In that case one of the board components should warm up. Can you check and figure it out?

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Ive tried like the dickens to get something to warm up. Haven’t felt anything. I have it connected to a DC power supply and it‘s set to 19.5 V, however it’s drawing basically zero amps, so nothing is going to get warm.

I suspect it’s a capacitor too, however, since a lot of things on the board are shorted, would that mean it’s more likely to be an IC?

[Weelcup]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

however, since a lot of things on the board are shorted, would that mean it's more likely to be an IC?

Simple answer is might be. But less likely.
And remember all 19v lines behind the second mosfet are connected together. So lets say one cap is sorted then all the 19v measuring spots will shows shorted. So "a lot of things shorted" are not valid. But more likely only one component is the cause.

Shorted to GND. I mean with zero resistance. Is most likely a defected cap behaviour. Basically because 99.99% of defects on caps making them direct line to GND. While in case of ICs then the resistance reduced but only rarely straight to zero.

Now worst case scenario is CPU or gpu short. Which mainly caused when one of the mosfet short between its source and drain. I mean the mosfets those feeding the cpu or gpu.

So never ever try to put the 19v directly behind the second mosfet or you will fry the cpu in case the fault is one of the cpu mosfets..

If you have an external power supply. You can try to inject no more than 0.5v to the short or behind the second mosfet where the 19v is missing due to the short.

This way you can safely check for the short and check for the hottest component. Again never inject 19v behine the second mosfet.

[mcplslg123]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

I agrre with @weelcup's suggestions but putting 0.5V may not heat up anything to be felt by hand. In my opinion putting upto 1.0V never damages the SOC/GPU.

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

So i jumped to the supply of the second mosfet. Sent about .75v which drew about an amp because .5v wasnt heating anything up. At 1 amp the GPU started to get warm ��

[Weelcup]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

So i jumped to the supply of the second mosfet. Sent about .75v which drew about an amp because .5v wasnt heating anything up. At 1 amp the GPU started to get warm ��

So you have some heating up. Lets pray the gpu to be ok.
It seems to me a shorted gpu mosfet.

What you should do now is to upload a pic of the gpu including all sorrunding mosfets. To let you know what to do next.

[Weelcup]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Sorry i forgot about the photos in you very first post above.
I have marked those rails. You can take them off the board by desoldering one side of each of them off the board. Each one of these rails is feeded by a mosfet.
So when you remove, for example the first rail then check if the 19v short is gone if not then desolder another rail.
Each rail is like a gray cube with two sided soldered to board. So basically by desoldering one of its sides you are cutting one line from the mosfet that feeding that rail and the gpu.

Remeber, check the 19v short if gone after you remove each of the rails. Once the 19v is no shorted then you can be sure that the related mosfet is shorted.

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

That worked! I found the defective MOSFET. Now the next challenge is finding a replacement ��

[mcplslg123]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Marking of the defective mosfet?? There may be an alternative.

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Marking of the defective mosfet?? There may be an alternative.

What else could I do?

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Here I've marked the defective MOSFET

[mcplslg123]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

@dakay, nothing is visible on your pic. I mean what is printed on that mosfet??

[Weelcup]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

That worked! I found the defective MOSFET. Now the next challenge is finding a replacement ��

Good.
Now can you share the number written on that mosfet?

From my experience it is very likely AON6936. Which is written as E6936 on the mosfet.

Kindely check it and confirm the number so we can tell possible replacement...

This is the datasheet for AON6936 ...

Remember it will be a bit challenging to desolder this mosfet as this board have a very good thermal mass. So you will need a good hot air soldering station.

[Dakay]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

Good.
Now can you share the number written on that mosfet?

From my experience it is very likely AON6936. Which is written as E6936 on the mosfet.

Kindely check it and confirm the number so we can tell possible replacement...

This is the datasheet for AON6936 ...

Remember it will be a bit challenging to desolder this mosfet as this board have a very good thermal mass. So you will need a good hot air soldering station.

AOE6930 is the MOSFET number. And I just found that out lol. Tried to get the MOSFET off and it took so long that a nearby capacitor blew. My hot air station is pants, so I just bought the Quick 861DW. Hopefully this will give me the heat I need.

Thank you so much for all your help!

AOE6930 datasheet:
https://cdn.badcaps-static.com/pdfs/...10bda3e70c.pdf

[Weelcup]

Re: HP Omen 17 - DAG3CMB1CH0 - 19.5v; 0amps

AOE6930 is the MOSFET number. And I just found that out lol. Tried to get the MOSFET off and it took so long that a nearby capacitor blew. My hot air station is pants, so I just bought the Quick 861DW. Hopefully this will give me the heat I need.

Thank you so much for all your help!

AOE6930 datasheet:
https://cdn.badcaps-static.com/pdfs/...10bda3e70c.pdf

Quick 861DW is excellent choice.
One trick that you can do is to use the iron station alongside with the hotair. However it would only be possible if the is a good space for the iron tip near to the mosfet pins.

In the procedure, you will apply the hot air on the mosfet and try to attach the iron tip on the base pins of the mosfet with a little amount solder on the tip to transfer the heat to the mosfet pad. Which in turn will make it easy for you to detatch the mosfet from the motherboard. Do not forget to use a good paste too. Also it might worth to remove the rail that is on that mosfet line bfore removing the mosfet . As rails also dissipating heat. .

But try not to keep hot air on the area for very long time to avoid bricking the board itself..