Lenovo G510 Slow Charging Problem

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

after remove diode,Ground of the regn pin 0,750 kohm.

First time I fixed it.

[mon2]

Re: Lenovo G510 Slow Charging Problem

Power up with the adapter and measure the voltage to ground of the REGN pin on the charger IC (without the diode).

What is the measurement?

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

0.015 v dc

[mon2]

Re: Lenovo G510 Slow Charging Problem

PU301 should be replaced.

https://www.aliexpress.com/item/3289...d=Y21vfUTHioJh
* be sure to select the BQ737 part #

Also review the part numbers of the mosfets linked to this charger IC. They are not expensive and should be available from the same store.

Consider to buy spares of all such parts.

AO4407AL @ PQ312, PQ301, PQ302
MDS1521URH @ PQ309, PQ310

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

I bought them all but estimated delivery date very late

If these still don't work when I change them?

[mon2]

Re: Lenovo G510 Slow Charging Problem

Start with the charger IC replacement. The LDO on pin #6 is a simple buck regulator that is required to accept the 19v from the adapter and lower it to ~6 volts. This part is failing to do this simple voltage output.

While waiting, perhaps consider to measure each voltage to ground reading of each pin on the charger IC again. Post the updated list.

The REGN pin must be ~6 volts to initiate the boost circuit required to enable the DCin mosfets. The gate pins of the DCin mosfets must be:

adapter voltage + boost voltage (REGN) = 19v + 6v = ~25v at the gate to ENABLE the power path between the power connector and the main logic board power rail.

If the gate pin remains at 19v or lower, the 2 * DCin mosfets will remain OFF. This is the voltage you are measuring at ACN / ACP, etc., etc.

ACDET must be > 2v4 as this is built on 2 resistors powered directly from the adapter. The resistors lower the 19v to a safe value for the charger IC.

All other indicators look to me to be ok but yet, REGN remains at 0 volts.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Hi mon2
Pu301 aftrr replacement,measurements attached.failure goes on.plug in adapter no adapter or charge led does not lit and no start with adapter.only power on battery.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Should I buy a new laptop ?

[mon2]

Re: Lenovo G510 Slow Charging Problem

Review pin #20 of the charger IC. This pin should fed by a 3 pin device which will be a dual common cathode diode.

One anode will be fed by the power rail supplied by the power adapter. The other anode will be fed by the battery.

Locate this part. Apply the power adapter only. Meter in dc volts mode (30v or higher is ok).

Measure the voltage to ground on each pin of this 3 pin device. The side with the 2 pins on the package will be the dual anode side.

In summary, the higher of the 2 power rails will power this charger IC.

Post the measurements of each pin. Confirm if the measurements are stable.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Are you talking about pq304,305,314?

[mon2]

Re: Lenovo G510 Slow Charging Problem

My bad, pin #20 is fed by the first DCin mosfet via P2. Confirm this voltage is stable.

Confirm again the voltage to ground of REGN pin #16. This should be ~6v under these conditions.

If not, remove all power. Meter in resistance mode.

Measure the resistance to ground of the same REGN pin.

[mon2]

Re: Lenovo G510 Slow Charging Problem

Forgot from earlier rework, the cap was removed from the REGN pin?

It must be placed back as the cap is required for the operation of this rail.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

I already placed the cap and diode back,after the replacement pu301.

Regn to gnd resistance 540ohm

[mon2]

Re: Lenovo G510 Slow Charging Problem

REGN is with a low resistance.

Are you confident of the soldering of the PU301 replacement?

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

I am waiting 6 may ,because coming new 24737 ic

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Hi ever body,

I replaced new charger ic after

Laptop start and works only battery.I plugged in adapter not lit charger led and dont charge battery.Does not work only plugged in adapter.

What can I do?

[mon2]

Re: Lenovo G510 Slow Charging Problem

Measure the voltage to ground of:

REGN
ACDET
ACOK
VCC

On the charger IC.

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

Regn 5.914V
Acdet 2.905V
Acok 5.889V
Vcc 19.96 V

[mon2]

Re: Lenovo G510 Slow Charging Problem

Good values.

What is the ACDRV voltage?

[ay_erdi]

Re: Lenovo G510 Slow Charging Problem

I can not find it,which pin is acdrv?