HP Gaming laptop 15-cx0812no no power on battery

[RickRockerr]

Hi!

My customer brought an HP gaming laptop with weird symptoms.

When the laptop is plugged in to AC, charging light lights up, but when the laptop is turned on, all the lights shut down and light up again in few seconds. When the laptop finally turns on, there's no problems whatsoever and everything seems to work like normal except for the battery.

Laptop shows that the battery is at 100%, but the laptop shuts down straight away when unplugged. HPs battery test says that everything seems fine.

Battery pins 4,5 and 6 give voltages 3V, 2.76V and 2.76V

I couldn't find any schematics for this board, but I assume that the intersil 88739A is the main power IC. 88739A gives the following voltages plugged to AC, no battery:
1. 2.1V
2. 2.7V
3. 3.1V
4. 3.1V
13. 3V
14. 0.1V
15. 0.1V
17. 0.8V
18. 19.4V
19. 5.3V
20. 5.3V
22. 0.1V
27. 17V
28. 11.8V
29. 19.6V
30. 24.7V

AC and Battery:
1. 2.1V
2. 2.7V
3. 3.1V
4. 3.1V
11. 1.9V
16. 2.2V
17. 0.8V
20. 5.3V
24. 4.9V
27. 17V
28. 11.8V
29. 19.6V
30. 24.6V
31. 19.7V
32. 19.7V


Only battery plugged:
3. 2.7V
4. 2.7V


I'm not very familiar with HP boards and would appreciate if someone could give a little help to get us to the right direction.

Images of the board here

[mcplslg123]

Re: HP Gaming laptop 15-cx0812no no power on battery

All the lights glows and shuts off in aloop for 2-3 times and then it works. right?? its 'coz of cmos reset as cmos cell is inside main backup battery. May be battery is faulty or any component on the output path from battery is shorted. Check which is the output pin on mb battery connector and see if the 10-12v from battery flows to the mb or not. Very likley a shorted cap/mosfet or battery itself.