Acer PT314-51s LA-K811P - No power on the battery

[tommy97]

I've uploaded pdf with part of schematics from BQ and it does seem to be correct as PRB27 & PRB25 are 10Ohm, PRB19 is 0.01Ohm

[Sephir0th]

Yeah, this was a shot into the blue. We have to start over for this new fault then. But maybe something odd at ACN/ACP then by any chance? Also it can be still another shorted Mosfet somewhere in the DC-IN circuit.

[mon2]

Is pin # 5 (ACOK) @ ~3v3? If not, the +3VALW rail is too low and should be reviewed. If the charger IC receives a high enough voltage @ ACDET (must be 2v4 or higher), then ACOK will tri-state (hi-z / high impedance) this signal line. Then the external pull-up resistor and pull-up voltage (ALW rail) must be present to soft pull this floating signal line to a logic '1'. The earlier list of voltages lists ACOK as a too low of a voltage.

[tommy97]

I've just got right BQ same as was installed, battery pin while battery & charger attached 12.08v, does not go up, have 2 batteries with exactly same measurement, ACDRV 25.9v, ACOK 3.27V

[tommy97]

Found out the problem, laptop work now on the battery, problem is with BATT_B/I does not go to 0V, while jumper is done on the battery connector to ground battery being charged, and laptop does work on battery & charger as well. Is that safe to leave it like that? If not, i can only suspect PQ201, i don't have replacement to test and i can't find it online.

[mon2]

Use 2N7002 for PQ201.

[tommy97]

Laptop fixed, I had problem with first mosfet (internal short in mosfet) and faulty diode pq201, I've replaced as well BQ however I did not confirmed if that was needed. Thanks for all help.