Asus P50IJ (Main K50IJ REV 2.3) no power on, no led, no charging battery

Good morning, this asus laptop has entered with the defect that does not turn on, no LEDs and does not recharge the battery. I don't read absorption with the bench power supply, checking the main board I find the voltage of 3v and 5v on two coils. Ec controller is powered because I find 3.3V on the ec power pins. I have not found traces of oxide on the board. I tried to reprogram the bios but nothing

It measures the voltage and resistance to ground on all the coils.
Measure the voltages on all pins of the battery connector with and without battery, power supply connected.

Thank's Machine
Test voltage resistance in big coil:
L8101 5,10V
L8102 3,36V
L8001 0V resistance 41ohm
L8002 0V resistance 410 ohm
L8301 0V resistance 930 ohm
L8201 0V resistance 12 ohm
Test voltage Without battery in battery connector:
PIN 1 1,50V AND SLOW DROP TO 0V
PIN 2 1,50V AND SLOW DROP TO 0
PIN 3 0V
PIN 4 0V
PIN 5 3,28V
PIN 6 3,28V
PIN 7 3,28V
PIN 8 GND
PIN 9 GND

Test with battery inserted:
PIN 1 0,37V
PIN 2 0,37V
PIN 3 0V
PIN 4 0V
PIN 5 3,27V
PIN 6 3,27V
PIN 7 0,14V
PIN 8 GND
PIN 9 GND
PIN 9

Perform the following measurements with connected power supply only (without battery connected):
- Measure the voltage to ground on pin 5 of chip U8801.
- Measure the voltage to ground on pin 3 of diode D1501.
- Measure the voltages to ground on pins 14, 17, 21, 74, 82, 83, 95, 107, 112, 128 of KBC chip.

- Measure the voltages to ground on pins 56, 125 of KBC chip in the following cases:
a) Power button released.
b) Power button pressed.

Thank's Matic
U8801 PIN5 0,70v

D1501 PIN3 3,22V

KBC:
PIN 14 3,26V
PIN 17 3,29V
PIN 21 0V
PIN 74 3,29V
PIN 82 0V
PIN 83 0V
PIN 95 0V
PIN 107 0V
PIN 112 0V
PIN 128 0,93V WITH LITTLE OSCILLATION

TEST KBC WITH POWER BUTTON

PIN 56 0V after pressy power button stay 0V
PIN 125 3,3V when press power button drop to 0V and when release power button go up to 3,3v

Check the transistor Q8801. If it is good, perform the following measurements.

Measure the voltages to ground on pins 1, 2, 3, 4, 17, 21, 24, 28, 31 of chip U8801 with connected power supply only (without battery connected).

Check the transistor Q8801. If it is good, perform the following measurements

Q8801 is ok, no short

U8801, no battery connected
PIN 1 19,36V
PIN 2 19,36V
PIN 3 19,36V
PIN 4 1,37V
PIN 17 0,04 V
PIN 21 0V
PIN 24 19,37V
PIN 28 0V
PIN 31 0V

The battery is bad, but the machine should work without it.

Measure the voltages to ground on pins 1, 2 of quartz X3001.
Measure the power consumption of the board without battery connected. Check, if the power consumption changes, when you press on the power button.

X3001:
pin 1 0,92v with fast oscillation
pin 2 1,54v

Test with Battery:
Matic, tests on the ic charger I did them without battery as you said, by connecting the battery there is no absorption, even by pressing the power button, no absorption.
I had done some checks on U8101 and I realized that the SUS_PWRG signals do not come out from pin 13 and 28

robgerr ha scritto:Test with Battery:
Matic, tests on the ic charger I did them without battery as you said.

Yes, I know. You also made some measurements with the battery in previous posts. The battery is definitely bad.

robgerr ha scritto:by connecting the battery there is no absorption, even by pressing the power button, no absorption.

Are you sure? I think there should be some power consumption (usually around 10mA). Please, check the power consumption again.

Hi Matic, back from the holidays and I'm back with this motherboard. So I measured the absorption directly with the multimeter, both with battery and without battery I measure 13mA of absorption. For safety I also tried to replace rt8206A (U8101) but nothing to do.

Please, specify the BIOS type number from the sticker on the RAM memory.

P501J (0203A)

Have you reflashed the BIOS chip with a proper type?
You should use a BIOS type P50IJ. Bios type K50IJ is probably not suitable here.

If not, I uploaded the BIOS dump P50IJ on the forum: www.elvikom.pl/asus-p50ij-mb-k50ij-rev-2-3-t61610.html

I try to flash bios for P50IJ from Asus Website (complete and not encrypted) but nothing, same problem

Measure the voltages to ground on pins 1, 2 of quartz X1501.

Measure the voltages to ground on pins 1, 2 of quartz X1501

0,25V in both pins

Try to reflow the Southbridge BGA chip (SLB8Q). If it does not change anything, replace this chip.
Be careful, because this chips are little more sensitive to heating than other classic BGA chips.