HP Pavilion 15S-FQ motherboard DA0P5HMB8J0 Rev J missing S5_ON

[Serbentas]

HP Pavilion 15S-FQ motherboard DA0P5HMB8J0 Rev J missing S5_ON.
Laptop gets 19V, light on, charges battery. No 3V and 5V because no S5_ON to enable them as far as I understand. Don't mind changing EC but Bios chip doesn't get 3V on pin 8 so how it will get firmware loaded?
No shorts anywhere
Please, any help anyone?

[mon2]

Does this board have a RTC coin cell battery? Replace it if yes. If not, test with a known good battery pack.

Which charger IC is onboard? Is there a schematic for this board? If not, share the details of the battery charger IC and then need the measurements from this charger IC for a review.

VCC
ACDET
ACOK
REGN (if applicable)

[Serbentas]

Don't think it has RTC battery. Its newer Intel i5 11th gen board. You mean get a new battery? Even if charging light changes to red and battery is charged? Sure, can order one.
Charging IC is BQ24728H. Attaching schematic shot.
VCC-19v
ACDET-2v
ACOK-no such a line, I guess its newer IC
REGN-3.1v

[mon2]

Hold off on the battery sourcing.

ACOK-no such a line, I guess its newer IC

This is ACPRES on your charger IC. What is the voltage to ground of pin #5 on the charger IC?

REGN-3.1v

Can you confirm this again? It should be ~6v. If still around 3v, remove all power -> meter in resistance mode -> test the resistance to ground of this REGN pin. Testing if there is a short on this low current rail.

ACDET-2v

Confirm this one too. It is too low and should be 2v4 or higher.

Are you using the official and proper rated power adapter on this unit?

[Serbentas]

ACPRES-3.01v
REGN-6v (sorry, before was measuring wrong pin)
ACDET-2.02v
Yes, using proper HP charger

[mon2]

Better measurements. Still concerned about ACDET which is often required to be > 2v4 to accept the adapter as a valid power source.

What is the voltage to ground of ACDRV pin #4 on this charger IC? This must be ~25v to enable the DCin power path mosfets which in turn will power the always on 5v and 3v3 missing power rails.

[Serbentas]

Tried different power on board (contains switch on button) and now it starts , fan spins but no display. Caps lock light blinking 3 long 2 shorts

[Serbentas]

One ram module or slot-works now fine with one. Thanks Mon ! Will look at other but that's basic. So on old power on board was missing mosfet: