HP OMEN 17 not power with AC

[Am0rPHiA]

Hi everyone

i have this laptop from HP with motherboard LA-H492P
it powers on with battery but not with ac

if i connect ac the battery it starts charging (led is orange on dc-jack)
if i press power then laptop powers on (using the battery) and battery stops
charging (dc-jack led turns white)

If i remove the battery and connect ac then laptop doesn't power on

The laptop motherboard is LA-H492P , i have replaced the battery charge IC
(iSL88739) but i still have the same symptoms.

I am uploading the schematic and photos in case someone can help me find the problem

Thanks

[Techtiger]

Re: HP OMEN 17 not power with AC

voltage on PU801 pin 1 2 30 31 32 29 & PQ801 all pis PQ803 all pin ?

[Am0rPHiA]

Re: HP OMEN 17 not power with AC

voltage on PU801 pin 1 2 30 31 32 29 & PQ801 all pis PQ803 all pin ?

you mean PUB01 (isl88739) ? i cant find PU801 in schematic

PIN 1 2.21v
PIN 2 2.85v
PIN 30 19.17v
PIN 31 19.05v
PIN 32 18.6v
PIN 29 19.65v

these are the voltages without battery connected

PQB803 has 19.17v on pins 1,2,3 and 19.7v on the rest

PQB801 has 19.7 on pins 1,2,3 and 19.17v on pin 4, 19.7v on pins 5,6,7,8

[Techtiger]

Re: HP OMEN 17 not power with AC

you mean PUB01 (isl88739) ? i cant find PU801 in schematic

PIN 1 2.21v
PIN 2 2.85v
PIN 30 19.17v
PIN 31 19.05v
PIN 32 18.6v
PIN 29 19.65v

these are the voltages without battery connected

PQB803 has 19.17v on pins 1,2,3 and 19.7v on the rest

PQB801 has 19.7 on pins 1,2,3 and 19.17v on pin 4, 19.7v on pins 5,6,7,8

ok my mistake PUB01 you ACDRVE voltage is low should be above +22V to 28V
do a cool checking no power multimeter ohms test S D G PQB01/3 both of them

[mobotest]

Re: HP OMEN 17 not power with AC

My HP laptop (DIFFERENT than your model) had similar symptoms.
If you want to try something quick for a possible fix, read further.

I had parts corresponding to MOSFETS PQB01, PQB03, PQB05 and CHARGE IC PUB01 replaced on my laptop.

Pin4 on PQB01, PQB03 should be about 25V to open the MOSFETS and let adapter voltage through to power the laptop.
Pin30 on PUB01 provides that voltage, but you have already replaced PUB01 so now replace PQB01, PQB03.

PQB05 is involved in charging the battery. Replace it if replacing PQB01, PQB03 does not solve all the problems.

FYI: PQB04 lets the battery voltage through to power the laptop. Since your laptop is booting ok from battery, PQB04 is ok.

Update this thread with the results.

[piernov]

Re: HP OMEN 17 not power with AC

FYI: PQB04 lets the battery voltage through to power the laptop. Since your laptop is booting ok from battery, PQB04 is ok.

No, PQB04 prevents the B+ current from flowing directly to the battery if both AC adapter and battery are plugged in.
If only battery is plugged in, current will flow from battery to B+ in any case since it'll flow through the body diode of PQB04. The charger IC should turn on PQB04 to reduce the losses generated by the body diode voltage drop.
If PQB04 is bad, in most cases it'll be shorted across drain-source, so that when AC adapter is connected the current will flow directly to the battery, in that case it can be harmful for the battery, so the BMS triggers over-voltage protection and the battery cannot be charged. Depending on how it works, the charger IC could also turn off DC-in MOSFETs since it may detect that something is wrong on battery charging rail.

[mobotest]

Re: HP OMEN 17 not power with AC

No, PQB04 prevents the B+ current from flowing directly to the battery if both AC adapter and battery are plugged in.

Yes, I agree. That is the additional function of PQB04 besides powering the laptop when only battery is connected.

If only battery is plugged in, current will flow from battery to B+ in any case since it'll flow through the body diode of PQB04. The charger IC should turn on PQB04 to reduce the losses generated by the body diode voltage drop.

PQB04 is NMOS which has to be turned on for current to flow between Source (pins1,2,3) and Drain (pin5). It is turned on by applying a voltage at Gate (pin4) higher than Source such that VGS (Gate voltage - Source voltage) > Vth (threshold voltage of NMOS).
So the charger IC needs to send a signal to Gate pin first, then channel is created between Source and Drain after which current flows powering the laptop from battery.

If PQB04 is bad, in most cases it'll be shorted across drain-source, so that when AC adapter is connected the current will flow directly to the battery, in that case it can be harmful for the battery, so the BMS triggers over-voltage protection and the battery cannot be charged.

Knowing laptop is able to boot from battery and also knowing it does not boot with only AC adapter, we can be sure PQB04 is ok and hence has no shorts.
Do you agree?

I gave my suggestions assuming the laptop owner has access to replacement parts, money is not an issue for doing the parts replacement, and wants to have a fully functional laptop ASAP.
Of course, if those are concerns or if the owner wants to actually learn how the power/ charge circuitry works and increase their knowledge, then owner should systematically debug to find the exact part(s) that is causing the problem.

[piernov]

Re: HP OMEN 17 not power with AC

Knowing laptop is able to boot from battery and also knowing it does not boot with only AC adapter, we can be sure PQB04 is ok and hence has no shorts.
Do you agree?

I don't, I just explained the opposite. PQB04 could be bad in this situation. It takes nothing to take out the multimeter and test it.

[mobotest]

Re: HP OMEN 17 not power with AC

I don't, I just explained the opposite. PQB04 could be bad in this situation. It takes nothing to take out the multimeter and test it.

I forgot to add that owner also stated battery charges when laptop is off. (My laptop also had this symptom)
Which could mean a source-drain short in PQB04 which triggers BMS over-voltage protection is unlikely.
Does that not validate that PQB04 is ok?

Yes, owner should definitely validate PQB04 as well because it is quick to do.
If money, getting parts are not an issue, could just go ahead and replace it as well.
I say this because 2 of the 4 MOSFETS that I replaced test OK off the board; so can never be sure.

[mobotest]

Re: HP OMEN 17 not power with AC

@Am0rPHiA

Any update?

[Am0rPHiA]

Re: HP OMEN 17 not power with AC

ok my mistake PUB01 you ACDRVE voltage is low should be above +22V to 28V
do a cool checking no power multimeter ohms test S D G PQB01/3 both of them

sorry for the late reply as i had a few days internet downtime,

using beeper mode PQB03 shows 550 and PQB01 buzzes like its shorted

using ohms mode (2M ohm) PQB03 Source is 400, Gate shows nothing and Drain is 400 (these numbers fluctuate a bit from 390 to 410)

PQB03 S 397 G nothing and D nothing also , i did the measurerments with black lead on ground and red lead on the legs of the mosfets

i will desolder PQB01 to see if it is really shorted

[Am0rPHiA]

Re: HP OMEN 17 not power with AC

My HP laptop (DIFFERENT than your model) had similar symptoms.
If you want to try something quick for a possible fix, read further.

I had parts corresponding to MOSFETS PQB01, PQB03, PQB05 and CHARGE IC PUB01 replaced on my laptop.

Pin4 on PQB01, PQB03 should be about 25V to open the MOSFETS and let adapter voltage through to power the laptop.
Pin30 on PUB01 provides that voltage, but you have already replaced PUB01 so now replace PQB01, PQB03.

PQB05 is involved in charging the battery. Replace it if replacing PQB01, PQB03 does not solve all the problems.

FYI: PQB04 lets the battery voltage through to power the laptop. Since your laptop is booting ok from battery, PQB04 is ok.

Update this thread with the results.

Thanks for the input, i will try and replace them and update on the progress

[Am0rPHiA]

Re: HP OMEN 17 not power with AC

@Am0rPHiA

Any update?

i removed PQB01 and discovered beneath a smalll wire connecting source to drain, apparently someone did this to bypass the fault and get 19v but it didin't work correctly but with the symptoms i described earlier.

now without the wire i have the following voltages

PQB01 drain 19v source 3.37v gate 4.8v

PQB03 drain 3.26v source 3.38v gate 4.8v

on PUB01

PIN 1 2.21v
PIN 2 2.85v
PIN 30 4.80v
PIN 31 3.24v
PIN 32 2.8V
PIN 29 3.37v

are there any known equivalents to replace PQB01 and PQB03?

[mobotest]

Re: HP OMEN 17 not power with AC

I replaced with exact part numbers on my board.

If you're asking about jumper wire techniques or something like that which will be a substitute to replacing the components, others on the forum may be of more assistance than I can provide.

[Am0rPHiA]

Re: HP OMEN 17 not power with AC

I replaced with exact part numbers on my board.

If you're asking about jumper wire techniques or something like that which will be a substitute to replacing the components, others on the forum may be of more assistance than I can provide.

i couldn't find those parts in other dead boards i have so i am hoping there are equivalent parts (there are lists with interchangeable mosfets/transistors etc)

but these part numbers are new (7th gen + boards) so not much info for interchangeabilty , EMP21N03HC and aon7380 are those that need replacement

i will order them but it could take a month to receive them

[mobotest]

Re: HP OMEN 17 not power with AC

I do not have such information on equivalent parts. You could compare the spec sheets and find out.

It might be a good idea to order PQB04, PQB05 also in case you need to replace them. This was you don't have to wait another month.

[Blackcoiin]

Re: HP OMEN 17 not power with AC

can somebody tell me which fuse is used as FU1 at this board ??