Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help!!

[roxboy1984]

Hi Guys,

Please could someone help I have a very strange issue with an HP 15-P104NI, The laptop wont boot unless the charger is connected despite the brand new battery. when I connect the charger with the battery installed the laptop takes forever to initialize the display but it eventually boots and the battery will say 100% however if I remove the charger it shuts off.

If i boot the laptop with the battery disconnected, the display initializes quickly and the laptop boots normally.

I have tested the battery as well as the charging current to the battery is good. it just seems like the motherboard wont allow it to switch to battery when the AC is unplugged. Its a fresh install of windows 11 and I have Re-flashed the bios so I'm confident its not a software issue.

Another strange thing that happens if I run the HP diagnostics on the battery it will freeze at 1% and not progress.

Does anyone have any idea what could be causing this? any help is greatly appreciated.

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Hi. You will have to review the charger IC area - specifically the mosfets surrounding the charger IC. This is as per above sticking from @Piernov.

Summary:

1) Locate the DCin power connector on the logic board. Post pics of the area if possible.

2) Near this connector will be 2 x DCin mosfets -> the mosfets will be driven by the charger IC. What are the markings on the charger IC ?

Perhaps the 'BQ' Texas Instruments IC? Share the full markings.

3) Near the charger IC will also be the HIGH & LOW side charging mosfets -> then are responsible to lower the DCin adapter voltage (~19v) to a safe and lower voltage to charge the battery pack.

4) In addition to the above will be a BATTERY MOSFET that is expected to OPEN/CLOSE when the battery ONLY is used. Most likely you have 1 or 2 mosfets that are leaking.

Start with the charger IC details and then we can review the datasheet for this IC and start troubleshooting. If they are the usual n-channel mosfets, they are not expensive to replace (often ~$1 USD or so each).

Do you have hot air tools for the repair? Or someone who may have it in your region?

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Thankyou so much for the reply and the information. I will do as you suggested and report back with pictures of the area. I really appreciate the help.

I'm busy learning how to troubleshoot and do component level repairs so I'm still a bit of a noob but I have a bit of an understanding of what you mentioned so will do my best.

I do have the necessary tools I'm sure. And I have donor boards around that I'm sure I can pull the mosfets from if need be.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Hi, So ive taken a few photos of my board. I dont have a microscope yet so im battling to read the info on the chips. please could you point me in the right direction of what i need to do next. I have also attached a Boardview and Schematic if that helps also.

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Schematic helps.

See attached for the power path.

Remove all power. Meter in resistance mode.

Locate mosfet PQ20 on your logic board.

Then (with NO POWER / NO BATTERY), check the resistance of this mosfet.

Datasheet for PQ20 = QM3016D is attached.

Measure the resistance of:

source & drain
source & gate
gate & drain

Post each measurement. If the resistance is low, then this mosfet is defective. Often the 2nd mosfet in the power path chain gets damaged and raises faults like yours. As per Piernov's sticky above on charger ICs.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Schematic helps.

See attached for the power path.

Remove all power. Meter in resistance mode.

Locate mosfet PQ20 on your logic board.

Then (with NO POWER / NO BATTERY), check the resistance of this mosfet.

Datasheet for PQ20 = QM3016D is attached.

Measure the resistance of:

source & drain
source & gate
gate & drain

Post each measurement. If the resistance is low, then this mosfet is defective. Often the 2nd mosfet in the power path chain gets damaged and raises faults like yours. As per Piernov's sticky above on charger ICs.

First of all thankyou for your help and patience I really appreciate it.

Ok so I've tested the following and these are the results. but its behaving strangely. sometimes when I test between drain and source on diode mode I get continuity and sometimes it gives me 500 ohms. Does this mean its faulty?

source & drain = 500 ohms (sometimes continuity)
source & gate = no reading (1 on multimeter)
gate & drain no reading (1 on multimeter)

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

On some meters, the '1' means that the resistance on the component is HIGHER than the scale used by the test equipment. So you must switch to a higher scale to make a measurement.

Either way, the 500 ohms is way too low. This part is defective. You will need to replace this mosfet. Either from a donor board or from a reliable vendor on Aliexpress / Digikey / Mouser / Arrow electronics.

QM3016D can be purchased here (suggest to also order some of the other mosfets surrounding the charger IC - as a precaution):

https://www.aliexpress.com/item/3287...d=1R0TIbuviT1D

https://www.aliexpress.com/item/1005...d=smaK26Qlbx3s

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Thanks so much I shall try and locate the component and replace it and will report back once i have to let you know if it worked... thanks again.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

I found a board that has one of these. from what i can see it seems to be the same spec. unless im missing something. do you think i could swop them out?

"p0603bdg Mosfet"

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Do check a few more items on the charger IC function.

Measure the voltage on the following points of PU1 IC:

ACDRV pin # 4 - this pin should be ~25 volts if all is well.

You may find this pin to be a lower voltage due to the defective PQ20 mosfet.

To confirm the operation of ACDRV, remove all power -> remove the resistor @ PR22 (~4k ohm resistor). After this resistor is removed, check the voltage of ACDRV again. It should allow for a voltage of ~25 volts.

If not, PU1 may be defective but confirm the voltage @ REGN (pin #16). Should be ~6 volts.

If you do not see the ~25 volts on ACDRV then you may need to order a replacement charger IC. They are all available on Aliexpress or donor boards.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

ok im getting 0 volts on ACDRV pin #4. I will have to try and remove the resistor but i may need to get someone to help me with this part or find someone with a scope as my eyes are not the best.

Random side note i tested another mosfet on a different board and got very similar reading to what i got with PQ20. so im just wondering if ive tested it correctly and its 100% faulty.

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Ok.

1) For the ACDRV check, meter in DC volts mode (30V or higher scale).

2) Red meter probe on ACDRV pin on the IC or better yet, the resistor that is in series with the same pin. It may be easier to probe.

Black meter probe to ground.

Do you have a voltage reading?

If not, confirm the meter is ok by checking the root power adapter voltage. It should be about 19 volts. This will confirm the meter is on the proper scale.

BTW - what is the voltage of REGN pin on the charger IC ? Again, may be easier to probe the capacitor (PC239) that is also on this pin of interest.

3) Next, on the mosfet check -> remove all power (no battery). Resistance mode on the meter. If you see a '1' then the resistance is too low.

Can you post a picture of the front face of your meter ? Configure it to the resistance mode you plan to use.

Also, if possible, take a picture of the measurement that shows ~500 ohms so we can confirm.

Another suggestion is to apply flux onto this mosfet -> with enough hot air but low air pressure (so other parts do not go flying) -> remove this mosfet.

Allow for the mosfet to cool down -> then measure the part while it is out of the circuit for the best measurements.

Proceed with the earlier suggestion to show the meter face when you measure the ~500 ohms.

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Yes, p0603bdg looks to be a good drop-in replacement for the QM3016D.

As a quick test, replace the one that you have onboard. Concerned about the missing ACDRV but may be linked to this mosfet.

Confirm you have REGN.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Ok.

1) For the ACDRV check, meter in DC volts mode (30V or higher scale).

2) Red meter probe on ACDRV pin on the IC or better yet, the resistor that is in series with the same pin. It may be easier to probe.

Black meter probe to ground.

Do you have a voltage reading?

If not, confirm the meter is ok by checking the root power adapter voltage. It should be about 19 volts. This will confirm the meter is on the proper scale.

BTW - what is the voltage of REGN pin on the charger IC ? Again, may be easier to probe the capacitor (PC239) that is also on this pin of interest.

3) Next, on the mosfet check -> remove all power (no battery). Resistance mode on the meter. If you see a '1' then the resistance is too low.

Can you post a picture of the front face of your meter ? Configure it to the resistance mode you plan to use.

Also, if possible, take a picture of the measurement that shows ~500 ohms so we can confirm.

Another suggestion is to apply flux onto this mosfet -> with enough hot air but low air pressure (so other parts do not go flying) -> remove this mosfet.

Allow for the mosfet to cool down -> then measure the part while it is out of the circuit for the best measurements.

Proceed with the earlier suggestion to show the meter face when you measure the ~500 ohms.

Ok so i have done most of what you asked.

I checked voltage on the Resistor attached to ACDRV and got 24 volts as you said.

I checked the voltage on cap attached to REGN and it was 5.9 Volts

I havent had a chance to remove the mosfet to get a reading as i dont have any flux so i need to get some first once i have flux i shall also try swop out the mosfet with the other one from donor board.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Hi,

Ok so i did everything you said. the reading are in the reply above. i managed to get some flux today and i remove the mosfet and did a reading which is attached and then i swopped out the mosfet with the other one from the donor board and the issue still remains. any other ideas? thanks so much

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

See attached. Your posted pic is in DIODE mode.

Switch to resistance mode (with the omega greek symbol). Select 2M scale.

Then measure and post the readings again. If the resistance is too low, the mosfet is defective.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

See attached. Your posted pic is in DIODE mode.

Switch to resistance mode (with the omega greek symbol). Select 2M scale.

Then measure and post the readings again. If the resistance is too low, the mosfet is defective.

Sorry excuse my ignorance i thought that Diode mode also measured the resistance.

So i did as you said and measured on "2M" and the reading im getting for all points is "1" on the meter again.

[mon2]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Short the 2 probes on the meter -> you should have ~0 ohms. Is this correct ?

If yes and you are confident that the meter probes are touching the mosfet pins then the '1' means that the resistance being measured is HIGHER than the scale setting.

Since 2M is the highest, this means the reading is higher than 2 Megaohms. This is a good reading and your mosfet is fine.

Remove all power / no battery. Check the resistance in the same way of the DCin mosfets on the logic board and post each reading.

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Short the 2 probes on the meter -> you should have ~0 ohms. Is this correct ?

If yes and you are confident that the meter probes are touching the mosfet pins then the '1' means that the resistance being measured is HIGHER than the scale setting.

Since 2M is the highest, this means the reading is higher than 2 Megaohms. This is a good reading and your mosfet is fine.

Remove all power / no battery. Check the resistance in the same way of the DCin mosfets on the logic board and post each reading.

Meter does go to 0 so its definitely working.

Here are the values of the other Mosfets. im not sure if im missing any?

PQ39
Source and Drain = .265
Source and gate = 1
Gate and drain = 1
PQ33
Source and Drain = 1
Source and gate = 1.501
Gate and drain = 1
PQ36
Source and Drain = .317
Source and gate = .101
Gate and drain = .526
PQ37 (I feel like this is Dodgy?) it even looks a little dodgy
Source and Drain = 014
Source and gate = .183
Gate and drain = .201

[roxboy1984]

Re: Hp 15-P104NI Laptop switches off with new Battery when AC unplugged!! Please help

Short the 2 probes on the meter -> you should have ~0 ohms. Is this correct ?

If yes and you are confident that the meter probes are touching the mosfet pins then the '1' means that the resistance being measured is HIGHER than the scale setting.

Since 2M is the highest, this means the reading is higher than 2 Megaohms. This is a good reading and your mosfet is fine.

Remove all power / no battery. Check the resistance in the same way of the DCin mosfets on the logic board and post each reading.

Any ideas based on the readings?