Lenovo G510 Slow Charging Problem

[mon2]

Re: Lenovo G510 Slow Charging Problem

Sorry - most of the BQ (TI) charger ICs feature the ACDRV pin. This model of charger IC on your logic board does not. My mistake.

See attached. The DCin mosfets are P-channel on your logic board (most other laptops are N-channel). With P-channel mosfets, the gate pin #4 voltage must be lower than the voltage being passed between source/drain pins.

Attach your adapter. Carefully measure the voltage to ground of each of the following mosfet pins:

source (1-2-3)
gate (4)
drain (5-6-7-8)

Repeat to test the 2nd DCin mosfet.

Post your measurements.

Q: Have you replaced only the charger IC at this time or also the 2 x DCin mosfets?

[mon2]

Re: Lenovo G510 Slow Charging Problem

Adding to your pile...

(from post #38) - concerned about the ACOK# voltage to ground.

On the charger IC used in this model, the ACOK# is an ACTIVE LOW signal.

So if the adapter voltage is OK (based on ACDET), this pin should be a logic LOW = 0 volts. But you are measuring a logic HIGH.

1) Connect the adapter and carefully measure this ACOK# pin # 5 voltage to ground. Best to measure at the charger IC pin if you can.

2) Remove the adapter (use the battery) and measure this pin voltage to ground again.

This is important because this pin is used to drive downstream 2N7002 mosfets which in turn enable / disable the 2 * DCin mosfets.

Summary: If this signal is logic HIGH, the 2 * DCin mosfets will remain disabled so the power adapter is NOT powering the logic board.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Sorry - most of the BQ (TI) charger ICs feature the ACDRV pin. This model of charger IC on your logic board does not. My mistake.

See attached. The DCin mosfets are P-channel on your logic board (most other laptops are N-channel). With P-channel mosfets, the gate pin #4 voltage must be lower than the voltage being passed between source/drain pins.

Attach your adapter. Carefully measure the voltage to ground of each of the following mosfet pins:

source (1-2-3)
gate (4)
drain (5-6-7-8)

Repeat to test the 2nd DCin mosfet.

Post your measurements.

Q: Have you replaced only the charger IC at this time or also the 2 x DCin mosfets?

Attached only adapter with measurements,

PQ301;
Pin 1 2 3 =19.98 V
Pin4=19.98 V
Pin 5 6 7 8=20.50 V

PQ302
Pin 1 2 3 =19.99 V
Pin 4 =19.99 V
Pin 5 6 7 8=1.66 V

After 6 may,coming new charger ic replacement pu301 and pq310.beacuse pq310 source and gate short circuit.

After this All replacement;motherboard working only adapter or battery and both.but no battery percentage full.

I has been measuremented to pu301 all pins only battery and adapter attached send to for you failure again.

At the moment only start battery.no attached adapter to determine.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Adding to your pile...

(from post #38) - concerned about the ACOK# voltage to ground.

On the charger IC used in this model, the ACOK# is an ACTIVE LOW signal.

So if the adapter voltage is OK (based on ACDET), this pin should be a logic LOW = 0 volts. But you are measuring a logic HIGH.

1) Connect the adapter and carefully measure this ACOK# pin # 5 voltage to ground. Best to measure at the charger IC pin if you can.

2) Remove the adapter (use the battery) and measure this pin voltage to ground again.

This is important because this pin is used to drive downstream 2N7002 mosfets which in turn enable / disable the 2 * DCin mosfets.

Summary: If this signal is logic HIGH, the 2 * DCin mosfets will remain disabled so the power adapter is NOT powering the logic board.

Only adapter plugged in pin5=5.88V
Only battery plugged in ping5=9.75V

[mon2]

Re: Lenovo G510 Slow Charging Problem

PQ301 was replaced?

Can you confirm?

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

I didn't replace it but if you want I can replace it

[mon2]

Re: Lenovo G510 Slow Charging Problem

The first mosfet is showing voltage on each side when it should be off but this is likely due to the internal forward biased body diode.

Remove the battery. Attach the power adapter.

Grab a piece of wire and connect one side to ground. Other side of the wire to pin #4 of either DCin mosfet (since they share pin #4).

Do this carefully to not touch pin #3 of the mosfet.

Does the laptop turn on?

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Does not turn on

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Pu301 all voltages down

[mon2]

Re: Lenovo G510 Slow Charging Problem

Remove all power and meter in resistance mode.

Measure the resistance across the mosfet pins on pq301 and the next DCin mosfet.

Source & drain
Source & gate
Gate & drain

Post each measurement.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

S D 113 kohm
S G 196 kohm
G D 285 kohm

[mon2]

Re: Lenovo G510 Slow Charging Problem

Measure also the next DCin mosfet.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Measure also the next DCin mosfet.

Relevant measurements pq301 with pq302

[mon2]

Re: Lenovo G510 Slow Charging Problem

Remove all power. Meter in diode mode.

Follow the process shown in step #1 here:

https://electronicsbeliever.com/how-...-is-defective/

Post your diode mode readings. Do test with probes in each direction.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

a little detail;

(ground to,related pin voltages

[mon2]

Re: Lenovo G510 Slow Charging Problem

The +3VALW voltage rail will only work once the adapter voltage passes through the 2*DCin mosfets.

The resistance looks a bit low for a good mosfet so best to check in diode mode as per the shared article. No power in diode mode checking.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Remove all power. Meter in diode mode.

Follow the process shown in step #1 here:

https://electronicsbeliever.com/how-...-is-defective/

Post your diode mode readings. Do test with probes in each direction.

I have been performed step 1 for pq301 and 302 for Pmos ;

two mosfets are good.

[mon2]

Re: Lenovo G510 Slow Charging Problem

What are the diode measurements?

Measure the resistance to ground of PQ302; Drain pins (5-6-7-8) = P3 in schematic.

When you connected gate pin # 4 of the PQ301/PQ302 mosfets to ground, what was the voltage on the drain pins (5-6-7-8) PQ302 ?

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

What are the diode measurements?

Measure the resistance to ground of PQ302; Drain pins (5-6-7-8) = P3 in schematic.

When you connected gate pin # 4 of the PQ301/PQ302 mosfets to ground, what was the voltage on the drain pins (5-6-7-8) PQ302 ?

pq302 diode measurements; 0,534v DC .

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

pq301 and pq302 diode measurements :0,534 V DC.

PQ302 drains to ground pins measurements;290 Kohm.