The battery is defective as this pin should not be 0 ohms when connected to the logic board.
This P_CLK pin is a signal that is used for communication with the logic board to share the battery properties, charge level, etc. Without this signal, the communication cannot proceed.
So I got a new original Asus battery and.... it's the same issue. Without battery laptop works on AC charger, but when I plug it in, it does not charge and works on the battery power.
But when I use some random 19V power supply, it magically starts charging. But only after a reboot. When I unplug and plug it again, then it starts using battery again.
With original PS it does not work even after a reboot
If you leave this battery mosfet off the board and continue to leave in the 'charge mode' with the power adapter, does the battery pack actually charge ?
Allow it to remain in this state for 30mins - 1 hour and check the voltage again on the battery pack - without the adapter.
What is the voltage of MBATV ?
Check if the attached thermal sensing parts are stuffed on your logic board.
1) check the voltages on ILIM (pin # 21) and ACDET (pin # 6) with the battery and charger attached. Still leave the battery mosfet (PQ23) off the logic board.
2) remove all power -> meter in resistance mode -> check the resistance values of the resistors @ ILIM (pin # 21). Do the resistor values match the schematic values ?
3) Does the BAT+ (battery connector voltage) increase when you apply the AC power adapter ? If not, the high side (PQ26) and low side (PQ27) mosfets need to be reviewed again.
With no power -> meter in resistance mode -> check the resistance across each mosfet pins:
source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate(4)
gate (4) & drain (5-6-7-8)
Post the measurements and the scale used on your meter for these checks.
I am not sure anymore, but I think I replaced the charging FETs from some other MB I had lying around. Now it has AON7410, it should have AON7506 according to schematic, but they looked simmilar enough for test. I can order new ones, but I doubt it will help
EDIT: yes I have replaced them, it's on first page, lol.
Do you have this circuit stuffed on your logic board ?
WITHOUT the battery, the mosfet (PQ88) should be OPEN. If PQ88 is open, PR531 will pull-up this line to ~3v. Review if you have PR531 onboard and also measure the +3VPCU rail. It should be present.
1) Post the voltages on each pin of the HIGH and also the LOW side charging mosfets (PQ26 & PQ27).
Source (1-2-3)
Gate (4)
Drain (5-6-7-8)
Also measure the voltage @ pin # 4 (GATE) of the missing mosfet @ PQ23 (battery mosfet).
2) Also need the voltage readings of the pins # 19 & 20 on the charger IC.
Voltage on ACOK pin # 5 of the charger IC ?
Voltage on ACDET pin # 6 of the charger IC ?
Do connect the battery during the above testing.
3) We want to leave out the battery mosfet (PQ23) till we can confirm the charger is working properly.
I have not replace it since the laptop worked on adapter just fine. But I have ordered 3 pieces to replace PQ21-23 and also 2 new charging FETs for PQ26 and PQ27. It should arrive next week, I'll let you know about the result.
I have no idea what happend, but after replacing the PQ21 and PQ22 the motherboard is dead again. I get 20V on VA+, but nothing on the VA. I put back original FETs, but nothing has changed.
When I plug in the battery it powers on normally, but still doesn't charge and now it doesn't run on AC at all.
I give up on battery charging, I just want the laptop to work on AC again as a desktop replacement. Is it bad idea to short VA and VA+ ?
Comment