Hp 15 la-d707p not power on .

[lapfix]

Hello friends .

I've got this lap la-d707p motherboard (With GPU) that is not starting. I have no power/charging LED on the connector when plugging the power charger.

I tested PQ202 and PQ203 the first 2 mosfet but i got only 19v at the drain of PQ202...

no short to GND at all coils , pq202 / pq 203 are not shorted.

Consumption is 0 amp. Gate of PQ 202 = 0v

BQ2472A requirements :

pin 20 vcc = 19v ok
pin 6 acdet =2.6v ok
pin 16 regn = 6v ok
pin 5 acok = 0v !! must be 3v

no 3vl at pr214 , no 3vl at pu2.

Troubleshooting :

i desolder pq203 , i got 24v at gate of pq202 , inject 19v at the pq203 ( non soldered) i got my 3vl ; acok = 3v...power on the lab work .

i changed pq 203 still same behaviour...what i must verify too !

thank you

[mon2]

Re: Hp 15 la-d707p not power on .

Remove all power. Measure the resistance across the same 2x DCin mosfets.

Review the other threads here for more details.

Post the measurements of each mosfet check.

[lapfix]

Re: Hp 15 la-d707p not power on .

Thank you mon2.

PQ 202 :
Source/drain = 17.84mohm
Gate /source = 10.76mohm
Gate/drain = 18.87mohm

PQ 203 .
Source/drain = 21.34mohm
Gate /source = 10.61mohm
Gate/drain = 22.51mohm


Yes i had reviw many threads but not the same issue

[mon2]

Re: Hp 15 la-d707p not power on .

Resistance is fine on the mosfets.

1) What is the voltage of BTST pin # 17 (PU201) ?

2) Confirm the resistance on PR209 (~4k).

3) Confirm that PR209 is connected to the source pins (1-2-3) of PQ203 and also connected to pin # 3 (PU201). This feedback pin (CMSRC) is important.

4) What is the voltage of CMSRC pin # 3 ?

5) If ACDRV is turned off, there may be a violation of one of the conditions for this charger IC. Confirm that the current sense leg of the circuit is working properly.

Measure the resistance from each side of the current sense resistor back to the charger IC. The traces must not be damaged or missing.

6) As a quick test, remove PR208 (4k resistor). Power up again.

What is the voltage of ACDRV at the pin # 4 (PU201) ?

[lapfix]

Re: Hp 15 la-d707p not power on .

Ok

pin 17 = BTST = 5.93v

PR209 = 4.11kohm
PR209 connectevity is confirmed.

pin 3 = CMSRC = 3.8mv

the current sense continiuty with pin 1/2 of pu 201 is ok.

PR208 = 4.11kohm...removed = not power on.

Pin 4 = ACDRV = 0v.


a violation of one of the conditions for this charger IC...i think yes because 3vl who supply acok is missing

[mon2]

Re: Hp 15 la-d707p not power on .

because 3vl who supply acok is missing

The pull-up voltage of +3VL is only on after the 2 x DCin mosfets are enabled (CLR) = +19.5VB

Is mosfet @ PQ201 stuffed on your logic board ? If yes, remove it for testing.

[lapfix]

Re: Hp 15 la-d707p not power on .

yes i know the 3vl and his supply ( pu2 ).
pq201 not stuffed.

[mon2]

Re: Hp 15 la-d707p not power on .

Replace PC213 on REGN with any value you can find but no lower than 1uf (6v or higher rated cap).

[lapfix]

Re: Hp 15 la-d707p not power on .

Why you have a doubt about it , btw i change it with same one from a donar board and same issue

[mon2]

Re: Hp 15 la-d707p not power on .

The REGN pin is linked to the charge (boost) circuit used for the ACDRV pin.

This was a suggestion from Tiger (TI FAE):

https://e2e.ti.com/support/power-man...acdrv-question

[mcplslg123]

Re: Hp 15 la-d707p not power on .

Battery discharge FET is not shorted or leaky??

[lapfix]

Re: Hp 15 la-d707p not power on .

@mon2 = i change pc213 and pu201 from a working motherboard...still same issue...o believe that pb is somewhere else.

@mcplslg..tthank you my friend...teste PQ205/206 with diode mode not shorted...i will desoldered for a good measurement = leaky or not

[mcplslg123]

Re: Hp 15 la-d707p not power on .

PQ204 is battery discharge fet and not PQ205/6.

[mcplslg123]

Re: Hp 15 la-d707p not power on .

Try replacing PC208/209/210 with exact same value.

[lapfix]

Re: Hp 15 la-d707p not power on .

Thank you mcplslg.
remplace it with the same from a donar board , same behaviour.
PQ 204 is OK tested with diode mode.

Notice : when i plug the cahrger ( from power supply ) the amp rise from 0.000 amp to 0.035 amp than 0.000 than 0.009...etc

I tested all the mosfets at this motherboard with diode mode all is Ok.

Any other suggestion !

[mon2]

Re: Hp 15 la-d707p not power on .

What is the voltage of ADP_ID ?

[mcplslg123]

Re: Hp 15 la-d707p not power on .

What about post#14??

[mon2]

Re: Hp 15 la-d707p not power on .

@mcplslg123,

Thank you mcplslg.
remplace it with the same from a donar board , same behaviour.
PQ 204 is OK tested with diode mode.

[lapfix]

Re: Hp 15 la-d707p not power on .

What is the voltage of ADP_ID ?

Yes i verify this from first and nothing unusual.

pin 75= 0.655v

as i said before , when charger plug in there's consumption but soon return to 0 amp...so i think that there's a leacky mosfet/capacator somewher...tht's complicates my research.

[mon2]

Re: Hp 15 la-d707p not power on .

no short to GND at all coils

Measure the resistance to ground of each and every coil on the logic board.

Check for any low resistance readings. Post any low readings to confirm.

Confirm that the traces from the charger IC pins ACN (1) / ACP (2) reach the current sense resistor @ PR203.