Lenovo Legion 5 15ACH6H - Battery charging but does not turn on

Hello,

Board markings are HY660 HY661 HY561 HY572 HY56C HY57K NM-D562 Rev 3.0.

On pressing the power button, power LED illuminates, but does not turn on. I have 20.5v, 5v, 3.3v and 1.8v present.

I have followed the advice given in https://www.elvikom.pl/lenovo-legion-5-plyta-nm-d562-rev-3-0-brak-1-2v-t77026.html?hilit=nm%20d562

KBC voltages are as follows:
pin 12 = 1.85v
pin 18 = 0v
pin 21 = 0v
pin 26 = 3.3v
pin 69 = 0v
pin 70 = 3.08v
pin 74 = 3.3v
pin 83 = 0v
pin 93 = 1.7v
pin 108 = 3.27v
pin 109 = 3.27v
pin 119 = 0v
pin 123 = 3.34v
pin 124 = 0v
pin 128 = 3.3v

pin 86 - power off = 3.3v
pin 86 - power button pressed = 0v
pin 86 - power on = 0v
pin 110 - power off = 3.27v
pin 110 - power button pressed = 0v
pin 110 - power on = 3.27v

I have cut jumper RC218 and the voltage on pin 86 with power on is 0v.

I have not tried reflashing the bios yet, so maybe that is the next step. 1.8v is present on the BIOS chip.

Voltage on pin 93 of the KBC is low. Check it again.
If it's less than 3V, measure the resistance to ground on pin 93

Have checked pin 93 again, voltage is 1.7V. Resistance to ground is 19.4kΩ.

Checking closely, the voltage might be correct. Some components are missing, as shown in the attached image.
Check if any components are missing.

Yes, on this board RC269, RC270, RC2711, QC6 and CC63 are missing.

Is the RTC battery charged?
There is no communication with the PCH inside the APU (it could be faulty).

RTC battery is reading 3.06V. The previous tests were carried out with the RTC battery disconnected. I remeasured the KBC voltages with the RTC battery connected, but the results are the same.