Acer Aspire ES1-571 (Mobo: DOMINO_BH MB 15300-1) - not powering on

Hello Everyone,
Acer Laptop has switched itself off while was in use.
After that is not possible to start again.
When I press power button:
- Blue LED flashes once
- Fan spins few times and stops
- 3,3V and 5V is present for around 5 seconds and both drop to 0V
Battery is getting charged normally. Can someone please help to solve the problem ?
Thank you in advance.
Rafal S.

Measure the voltages on pins 11, 12, 15 of PU4502.
Measure the voltages on pins 11, 12, 17 of PU4501.

Hello Machine,
Thank you for your support.
I have measured required voltages:
1st scenario before pressing power button:
Measure the voltages on pins 11 (19V), 12 (0V), 15 (5V) of PU4502.
Measure the voltages on pins 11 (19V), 12 (0V), 17 (3.3V) of PU4501
2nd scenario after pressing power button:
Measure the voltages on pins 11 (19V), 12 (3.3V and drops to 0V after 5 seconds), 15 (5V) of PU4502.
Measure the voltages on pins 11 (19V), 12 (3.3V and drops to 0V after 5 seconds), 17 (3.3V) of PU4501

Measure the voltages on pins 1, 2, 6, 8, 9, 10, 22, 27 of PU4801.

Hi,
I have measured in 2 scenarios again:
Before pressing power button:
Measure the voltages on pins 1 (0V), 2 (0V), 6 (0V), 8 (0V), 9 (0V), 10 (0V), 22 (19V), 27 (0V) of PU4801
After pressing power button:
Measure the voltages on pins 1 (0.1V and drops to zero right away, 5.9 MΩ resistance), 2 (0.3V and drops to zero right away, 113 Ω resistance), 6 (0.2V and drops to zero right away, 540 Ω resistance), 8 (0.5V and drops to zero right away, 4.7 kΩ resistance), 9 (5.1V and drops to 0V after 5 seconds), 10 (5.1V and drops to 0V after 5 seconds), 22 (19V), 27 (4.8V and drops to 0V after 5 seconds) of PU4801
Thank you for your help.

Measure the voltages on pins 32, 36, 95, 97, 99, 101, 106, 107, 110 of KBC.
Measure the voltages on pins 114. 115 of the KBC in the following cases:
at power off
with pressed power on
to power on.

Hello Machine,
Thank you for your continuous help.
Measure the voltages on pins 32 (0V, when power button pressed 0.9V and drops to zero right away), 36 (0V, when power button pressed 0.9V and drops to zero right away), 95 (0V, when power button pressed 3.3V and drops to zero after 5 seconds), 97 (0V, power button pressed and still 0V), 99 (0V, power button pressed and still 0V), 101 (0V, when power button pressed 3.3V and drops to zero after 5 seconds), 106 (0V, power button pressed and still 0V), 107 (0V, when power button pressed 3.3V and drops to zero after 5 seconds), 110 (0V, power button pressed and still 0V) of KBC.
Measure the voltages on pins 114. 115 of the KBC in the following cases:
at power off (pins 114 - 3.2V , 115 - 0V)
with pressed power on (pins 114 - 0V , 115 - 3.3V but drops to zero after 5 seconds)
to power on.

Lack of communication with the PCH contained in the APU.
Attempt a reflow on the APU.
Surely a reballing / better replacement will be necessary.

Hi Machine,
Changing APU for this generation is not economical repair.
I should be able to buy used working board.
Thank you for your time and help.