Dear mon2,

I have checked the main 6 inductors, and it did not beep. Values measured goes from 0.4 to 1.8. Please note that as the IT897 and the inductors are located in opposite sides of the board, I had to place my probe on another component on the same side of the board as the inductors (I used the boardview to find another component on the +3V signal on the other side of the board).

Besides, the boardview does not indicate that an inductor (PLxx) is located on the net of the +3V signal:



Regards,
mkdj...

Dear mon2,

By searching the signals in the Boardview file I can't find any signals called ALW or ALWON.

However, I have found the EC chip, which is the IT8987. I have found another schematic of this EC to find out which PIN should receive power :


If I am right, VCC should be on pin J5 of the EC.

Looking now at the boardview of my ASUS, pin J5 should be fed by a signal called +3V. However, when I measure the +3V signal anywhere on the board, it gives me 0V. To me, that means that the +3V power rail is not created, and the EC can't be powered,...

Dear mon2,

Thanks for being here again. Please find below the voltages to ground on pin#1 (ACN) and pin#2 (ACP) of the charger IC (BQ24780). Note that I am using a lab power supply which I have set to 19.7V output.

With the power supply only:
pin #1 : 19.68V steady
pin #2 : 19.68V steady

With the power supply AND the battery:
pin #1 : 19.49V steady
pin #2 : 19.49V steady

Regards,
mkdj

Dear all,

Without battery but with the charger, I have checked voltage to ground of every inductor on the board. I have 0V everywhere, except at the PL19, which is the inductor closest to the battery connector. Here I got a voltage fluctuating around 8V. According to the boardview, this is VBAT voltage.

Without power, I have also measured all resistance to ground of each inductor. I have fairly low values on some of them. I have indicated the voltage they should deliver (signals taken from Boardview):

42 Ohm @PL8 : +0.95V_VCCIO (looks like it goes mainly...

Thank you very much mon2 for the time you spent with me on this board. I will continue investigating next Monday. I will keep on feeding this post with my updates, so that it can help others.

Regards,
mkdj

Dear mon2,

My mistake, I indeed measured the wrong pins on charger IC. Find below correct values:
- Voltage at the ACDRV pin on the charger IC (pin #4) is 25.77V.
- REGN voltage (pin #24 of charging IC) is 6.02V.

Characteristics of the battery mosfet:
MOSFET AON6414AL (from boardview)
6414A GL0S15 (from topside marking)
N-Channel (according to datasheet)​

There is charge on the battery (this is the first thing I tested, before extracting the motherboard, see first post). I have checked one more time, and my ampmeter says the...

Dear mon2,

With adapter plugged in:

- Voltage is indeed 25.76V stable at the gates of the two DCIN MOSFETS.
- Voltage at the ACDRV pin on the charger IC (pin #4) fluctuates between 6.86 and 8.40V.
- REGN voltage (pin #24 of charging IC) is 0V.

I don't know if it is relevant, but I have checked voltages of the battery MOSFET with the adapter plugged in, and no battery present:
- Source voltage: fluctuates between 6.89V and 8.40V
- Drain voltage: stable 19.8V
- Gate voltage: fluctuates between 6.83V and 8.40V

Regards,...

Dear mon2,

Not sure if I understand the first question correctly, but charger IC is BQ24780.

DCIN MOSFET #1 (PQ20)
N-MOSFET AONS32306 (from boardview)
32306 GL9A1F (from topside marking)
N-Channel (according to datasheet)
source - drain : 1.94 MOhm
source - gate : 2.57 MOhm
gate - drain : 3.74 MOhm

DCIN MOSFET #2 (PQ21)
MOSFET AON6414AL (from boardview)
6414A GL0S15 (from topside marking)
N-Channel (according to datasheet)
source - drain : 2.76 MOhm
source - gate : 2.56 MOhm
gate - drain...

Thank you mon2 for you help. Below are the readings of voltage to ground of each pins of the battery connector.

• 1 : fluctuating between 6.86 and 8.40V
• 2 : same behavior as pin #1
• 3 : almost stable (fluctuates within a 3.29-3.30V range)
• 4 : almost stable (fluctuates within a 3.28-3.30V range)
• 6 : 0V
• 7 : 0V
• 8 : 0V

...

Dear all,

I am still investigating on this board.

As said before, when no battery is present, the charging chip PU13 (BQ24780) gives unstable 24780-BATDRV signal, fluctuating between 6.9 and 8.4V. However, signal VIN is 19V after the shunt resistor.

If we have power on the main power rail, does that mean that the charging chip BQ24780 is good? Or can we have 19V on the main power rail AND a faulty charging chip which prevents the laptop from turning on?

Many thanks for your help,
mkdj

Hello everyone,

Mark and model: ASUS X571
Symptoms: not turning on. There is only the LED battery indicator working. The owner of the laptop told me this problem arrived one week after having changed the battery. He then managed to power on the laptop only once, and then it never powered on again.

Tests already made:
- Battery is charging when laptop is plugged in. The LED battery indicator turns white after a couple of hours of charge, indicating that battery is fully charged. However, laptop won't turn on anyway, with or without AC plug.
- I have removed...