HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

[TTR]

HP Envy X360
Motherboard:Laduree 1.0 MB 14257-2
CPU:SR23W i7-5500U
KBC:ENE KB9028Q C

At first, the board was dead no lights nothing after connecting the charger.

After visual inspection, I noticed damaged components in the charging circuit:
PR4408, PR4415, PR4416, PU4406
I replaced them (including high side and low side MOSFETs PU4406 and PU4405).
Later on the 20th leg of the charger, I still had low resistance, so I replaced the charger chip
After replacing the charger chip I have a white led when I plug the charger.

At this moment laptop behave like this:
After I press the power button the light on the power button blink white for a second a fan twitch for a little
After further measurements, I've noticed no voltage 3.3v and 5v on coils PL4501,PL4502

Here are my measurements:
Resistance on coils :
PL4501 - Resistance in mega Ω
PL4502 - Resistance in mega Ω
PL4901 - 660k Ω
PL1 - Resistance in mega Ω
PL4701 - 62.9 Ω
PL4801 - 233k Ω
PL8201 - 21 Ω

PU4503
Pin 3 (VREG3) - 3.29v
Pin 6 (EN2) - 0v
Pin 12 (VIN) - 19.5v
Pin 13 (VREG5) - 5v
Pin 20 (EN1) - 0v

Resistance:
Pin 6 (EN2) - 12k Ω
Pin 20 (EN1) - 12k Ω

U2401
Pin 67 (AVCC) - 3.29v
Pin 91 (5V_S5_EN) - 0v
Pin 101 (3V_S5_EN) - 0v
Pin 103 (RSMRST#) - 0v
Pin 110 (ACIN#) - 0v
Pin 111 (VCC) - 3.29v

Looks like KBC doesn't issue a turn-on signal for 3v/5v driver chip.
I've tried to reprogram Bios and KBC chip with a dump from HP update and still, nothing changed, then I replaced KBC with a new one and programmed it with a dump from HP update and still nothing.
I'm out of ideas right now.
Thank you for any help and ideas on what I should do next.

[mcplslg123]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

Link the schematic if available. What is the measurement for ACOK/ACDET/VCC/REGN pins??

[TTR]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

Schematic is available link is down below
https://drive.google.com/file/d/1CxX...JchV4hgRl/view
Here are my measurements
5 - ACOK#- 0v
6 - ACDET- 2.6v
20 - VCC- 19.4v
16- REGN- 6v

[mohammed mohan]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

Thanks

[TTR]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

Any ideas ?

[mon2]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

What is the voltage of ACDRV pin on the charger IC?

Check the voltage on the gate pin #4 of the 2x DCin mosfets.

Post all measurements.

[TTR]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

What is the voltage of ACDRV pin on the charger IC?

Check the voltage on the gate pin #4 of the 2x DCin mosfets.

Post all measurements.

Can't find ACDRV pin on my charger IC.
I'll attach a part of schematic with my charging ic.


On the gate of PU4402 and PU4403 I have 6.5V

[mon2]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

For P-channel mosfets, the GATE voltage has to be more negative than the voltage it is passing to enable. Looks ok @ pin #4.

Remove all power and check the resistance across the mosfets.

[TTR]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

For P-channel mosfets, the GATE voltage has to be more negative than the voltage it is passing to enable. Looks ok @ pin #4.

Remove all power and check the resistance across the mosfets.

PU4402
S-D 340k
D-S 340k

D-G 290k
G-D 290k

S-G 125k
G-S 125k

PU4403
S-D 235k and rising
D-S 235k and rising

D-G 400k and rising
G-D 400k and rising

S-G 100k
G-S 100k

[Sephir0th]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

It's a HP. You're working with known good charger of correct wattage?

[TTR]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

It's a HP. You're working with known good charger of correct wattage?

I have tried with 2 different know good hp 65w chargers and got the same results.
Later I connected board to lab power supply with a prepared HP cable with resistor between + and ID pin which simulated 90w power supply

[mon2]

Re: HP Envy X360 Laduree 1.0 MB 14257-2 turns on and off

U2401- Pin 103 (RSMRST#) - 0v

Being an active LOW signal, this pin is stuck in reset mode.