OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

[sikocan]

Laptop: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574
Problem: Charger is not being detected hence it won't supply power to the system ( my diagnosis so far )
Charger light not turning on on the DC Jack when plugged in.
MOSFET 1, turns on and off continuously as seen in thermal camera, I have replaced MOSFETs and all the same issue, I have checked all 3 mosfets outside in diode mode and they open and close fine. I have put all mosfets back. The TI738 looks good. I can't located current sensing resistors as I dont have schematics.
The gate of mosfet 3 connected to Pin 4 of TI 738 which is ACDRV

bq738 datasheet https://cdn.badcaps-static.com/pdfs/...ab833061ef.pdf
I have tried different DC jack as well same issue
Pin 1 and 2 of TI 738 are ACN / ACP and both are 0.35 ohm which I think are fine.

Battery is not showing any voltage when inserted into laptop - I assume BMS protection has kicked in.


when I injected 1v into source of MOSFET 1, it's taking in 0.96a at 1V for an N Channel this is fine. when I insert 19v into DC jack 19V pin - the mosfet as you can see switching ON and Off same can be seen on the power supply. see video below

None of the pins of the DC in jack are grounded except the ground.

i think problem is elsewhere and not around these mosfets.. i'll dig deeper I suspect something to do with battery area

All the coils also look good, nothing 0hms

I'm so tempted to run a wire but I don't want to for Mosfet 1.

wire is not the solution - any ideas anyone?

Power Supply Activity Video
https://youtu.be/RoyAInHnsWM

Thermal Cam Readings
https://youtu.be/elV3R0ht2Ms

[sikocan]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

TU117-750-A1 GTX1650 TI N18P-G0-MP-A1 GPU Coil is showing 0.60 Ohms - I suspect this is the issue. When 1V applied, it takes about 0.8-0.9amps and goes straight to GPU at about 50 degrees

[mcplslg123]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

Your dc supply readings indicate a possible short in +19V line. Measure the voltage on drain as well as resistance on any high side mosfet to confirm. BQ738 readings for pin4/5 and pin6??

[sikocan]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

So you don't think the GPU is shorted even though the coil is showing 0.6 ohms?

[sikocan]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

I've assembled the laptop fully back. I'll disassemble again for the sake of troubleshooting again.

[ktmmotocross]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

check all mosfets for short and if u dont have one, inject 1V 10A after SHUNT RESISTOR and check with thermocam for burning component. NEVER inject 19V, because if u have shorted highside mosfet, u BURN GPU,CPU or other expencive IC

[mcplslg123]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

So you don't think the GPU is shorted even though the coil is showing 0.6 ohms?

Yes, GPU is not likely shorted. Low resistance is the norm there.

[sikocan]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

Hi all, thanks for the help so far. yes it's the 19V rail is shorted. Attached are more images for your reference in the above post.

In terms of the BQ738 readings are below:
Resistance to ground on Pins:
1 0.4
2 0.4
3 3.43k
4 4.53k
5 29k
6 36k

Voltage:
1 Constant 0
2 Constant 0
3 Constant 0
4 0.12 Up and Down to 0
5 0.3 Up and Down to 0
6 2V

[sikocan]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

Thank you for your help ktmmotocross and mcplslg123.
I did found a bad cap around Audio IC which I never expected, at 1V 1.5amp I was able to detect around 48 degrees and focused on it to find a dead short cap.

[facarr]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

I had the same Iusse, but when I changed the cap, and Press the power button, The EC burn.

[CossaK]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

what was the problem? can I get a picture of what needs to be replaced?

[android927]

Re: OMEN by HP 15-dc1093tx G3DD (DAG3DDMB8C0) 08574 Power Issues

Thank you for your help ktmmotocross and mcplslg123.
I did found a bad cap around Audio IC which I never expected, at 1V 1.5amp I was able to detect around 48 degrees and focused on it to find a dead short cap.

I literally had the same issue with the same board, and just like you it ended up being a shorted capacitor near the audio IC. I wonder if there is some sort of design flaw in the audio circuitry.