Lenovo G40-80 ACLU3 ACLU4 NM A362 not charging

[G_sene]

Hi, everyone.

I have this notebook that won't charge.
In Windows, the charger icon doesn't appear on the battery, but the charger turns on the notebook normally.

PU301:

Pin 5 (ACOK) - 5.97v
Pin 6 (ACDET) - 1.83v (should have 2.6)
Pin 16 (REGN) - 6v

PQ308 has no gate voltage, so it doesn't drive PQ309 low

With the battery connected, its voltage goes the reverse way to the jack, having 14v and not 20v:

PQ301 e PQ302

Pinos 1,2,3 14v

Pino 4 5v

Pinos 5,6,7,8 com 14v


Without battery:

PQ301 e PQ302

Pinos 1, 2 e 3 = 20v

Pino 4 = 9v

Pinos 5, 6, 7 e 8 = 20v

[mon2]

Pin 6 (ACDET) - 1.83v (should have 2.6)

Yes.

Check the resistance of PR310 and PR311. Do so without power to the machine. Each should be close to the schematic values.

[G_sene]

Yes.

Check the resistance of PR310 and PR311. Do so without power to the machine. Each should be close to the schematic values.

The PR310 has 214k, off the board it has 390k.

The PR311 has 54.97k.

[Sephir0th]

Since the resistors appear to be in tolerance, another possibility would be a too low voltage at VIN (PR310 Pin 2) or the charging controller pulling ACDET low for some reason (faulty charging controller).

Edit: missed the part with the reverse voltage. This is definitely not okay. Did you check PQ301 and PQ302 for being internal shorted? even if it is only partial.

These Mosfets shouldn't be activated in battery mode by pulling the Gates low.(dunno whether you checked that with battery only). And from my understanding PQ303 (Bat-to-sys-Fet) and PQ309 (Charging high-side) should be checked too. Because obviously the battery is supplying the main power rail even though the charger is plugged. And it shouldn't be like that.

[G_sene]

Since the resistors appear to be in tolerance, another possibility would be a too low voltage at VIN (PR310 Pin 2) or the charging controller pulling ACDET low for some reason (faulty charging controller).
Edit: missed the part with the reverse voltage. This is definitely not okay. Did you check PQ301 and PQ302 for being internal shorted? even if it is only partial.

These Mosfets shouldn't be activated in battery mode by pulling the Gates low.(dunno whether you checked that with battery only). And from my understanding PQ303 (Bat-to-sys-Fet) and PQ309 (Charging high-side) should be checked too. Because obviously the battery is supplying the main power rail even though the charger is plugged. And it shouldn't be like that.

I have no short in PQ301, PQ302, PQ309 and PQ303.

[mon2]

Connect only the battery.

Measure the voltage to ground of:

BATT_OUT
PACIN

Then connect also the adapter. Battery to be still connected. Repeat the above measurements. Post each value.

[G_sene]

Connect only the battery.

Measure the voltage to ground of:

BATT_OUT
PACIN

Then connect also the adapter. Battery to be still connected. Repeat the above measurements. Post each value.

Battery connected:

BATT_OUT - 0V (PQ996)
PACIN - 2.05v (Only in PQ307. PQ308 and PQ998 has no voltage of PACIN)

Adapter and battery:

BATT_OUT - 0V (PQ996)
PACIN - 2.08v

[mon2]

Confirm the following...

Review the mosfet @ PQ998B. It does not appear to be working.

ACOK = ~6v (from post #1) -> then is the gate voltage for PQ998B so this mosfet should close and drive PACIN to a logic level of '0' when the power adapter is mated. PACIN is stuck @ ~2v. Confirm it.