NO POWER HP Pavilion Gaming 15-ec0013dx

[savemydevice27]

NO POWER HP Pavilion Gaming 15-ec0013dx after prior attempt at battery replacement. Customer stated they slipped with a screw driver shorted a component out near battery connector and caused a spark.

Poked around with meter and found a short on the source legs on B20N03 mosfet (image attached). Mosfet looked a little burnt so I pulled but short remains on source. Looking for schematics or help further diagnosing.

Motherboard info: DA0G3HMB8D0 rev: D
Model : G3HA

[mon2]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

The source pins = pin # 1, #2 and #3 are grouped together so they will appear as a short. You can review the bottom side of the same part and there will be a thick grouped trace across these 3 pins.

Likewise, the drain will feature pin # 5, #6, #7 and #8 to be grouped together.

This is done to spread the current across multiple contact pins ('sharing the burden').

You can check if the mosfet is truly defective by reviewing the resistance across the mosfet pins:

< remove all power; no battery & no power adapter >

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)


reference:
http://electronicsbeliever.com/how-t...0good%20MOSFET.

see the resistance method of testing at the above webpage.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

No, all source pins 123 are short to ground. I don't think that's normal. I may be wrong though.

[mon2]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Can you link the schematic, if you have it?

The source may be truly connected to ground. This mosfet could be the low side mosfet of a power rail.

What is the exact resistance reading? Short your probes on the meter, same reading?

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Yes, 0 ohms of resistance in diode mode. And I don't have schematics unfortunately.

[Sephir0th]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Also in my opinion that's just a normal buck converter with of course one MOSFET connected to GND. Source of the MOSFET in question is connected to GND while Source of the other MOSFET is connected to Phase is another indicator.

With the zoomed in picture of the initial post nobody can do anything. And really, if you continue with the hunt for bad low-side MOSFETs it might went to be a endless repair attempt.

Share resistance to GND of each Coil and the main power rail (at CSR) instead if you want to make progress.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Not to sure where to measure. I typically do iphones only. Trying to expand. Thanks for help. Let me know if any of that helps. =)

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

picture attached.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Update on BQ

[mon2]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Post pics of where the external power adapter powers this logic board -> nearby will be 2 x DCin mosfets. They are of interest.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

charger charges laptop via a cable that runs to the MB. Here is the backside of where the cable connects to.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

here is what i mean

[mon2]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

When you power these boards with the proper external power adapter, are you able to measure any voltage on any of these mosfets?

The 2 x mosfets near the battery connector will be the HIGH & LOW side mosfets that charge the battery.

Before this can even happen, the BQ charger IC needs to be powered.

Respectively, locate where the DC adapter connector is located -> the 2 x mosfets in this region are of interest.

After these 2 x mosfets will be the BQ charger IC.

Post pics of the DC adapter connector and region.

You show mosfets on BOTH sides of the PCB -> check which ones are connecting to the DC adapter connector.

Update - ok - see you holding the adapter connector. This is new to me.

Now confirm that the mosfets nearby are connecting to the white nylon connector with a resistance check.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

The 19v dc connector from charger is working correctly. Have 19v on the diode. I have continuity from the red side of the dc in to the back mosfets pictured.

[mon2]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Ok. Remove all power. Meter in resistance mode. Follow the suggestions in post #2 to check the resistance across the same mosfet pins.

Post each measurement and the meter scale used for the resistance checks.

So for example, source (1-2-3) & drain (5-6-7-8) - what is the resistance?

Interested in the readings of both mosfets.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Okay so this is new testing to me, but I think I understand.

Top mosfet with meter in diode mode
Red probe on source and black on drain is .668
Black probe on source and red on drain is open

Red probe on source and black on gate .478
Red probe on drain and black on gate its open, then if I put red probe back on source its opened (short to ground.)


Bottom mosfet with meter in diode mode
Red probe on source and black on drain is .668
Black probe on source and red on drain is open

Red probe on source and black on gate .478
Red probe on drain and black on gate its open, then if I put red probe back on source its opened (short to ground.)

Both performing the same.

[mon2]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Actually, no. Meter in resistance mode. You should see the greek symbol (omega for ohms).

Then perform your testing.

So one meter probe (either color) on source pins (1-2-3) - pick anyone.

Other meter probe to drain pins (5-6-7-8) - pick anyone.

Record the RESISTANCE. Out of habit, just learned with resistance checks.

Post each measurement. No power during these tests on the logic board !!

Do also post the meter scale used during these tests.

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Aright thanks for clarification.

I have my meter in ohms mode on the 200m setting. Lower settings (20m/200k/20k didn't show any reading.)

Top mosfet
Black probe on drain and red on source I get 1.1. Reverse probes it shows reading for 2 seconds as it climbs rapidly to OL. (15, 40, 80, 150)

Bottom mosfet
Black probe on drain and red on source I get 1.1. Reverse probes it shows reading for 2 seconds as it climbs rapidly to OL. (15, 40, 80, 150)

[savemydevice27]

Re: NO POWER HP Pavilion Gaming 15-ec0013dx

Hopefully that helps