Toshiba C75D no Power With Battery

[ahkh_72]

Hi
I received a Toshiba laptop that does not turn on with battery and the orange indicator flashes.
Even if the battery is connected, it does not turn on with the adapter.
(it turns on without battery)

I replaced the charge controller(BQ24725a), IO (NPCE285UA0DX)and battery but the problem was not solved.

The input and charging MOSFETs are also correct.

I don't know what to test anymore?
Thanks for any help.

MB:AR10AN-6050A2632101-MB-A01

[ahkh_72]

Re: Toshiba C75D no Power With Battery

Meanwhile, when the laptop is on and Windows is up, I connected the battery and it showed the charge percentage.
But when I pulled the charger out, the device turned off.

[mon2]

Re: Toshiba C75D no Power With Battery

Review each of the power path mosfets.

Be sure the battery is a known good battery. If possible, test with another battery.

Review PQ5 which is the battery mosfet that should enable if on battery only; turn OFF if the power adapter is plugged in.

[ahkh_72]

Re: Toshiba C75D no Power With Battery

Review each of the power path mosfets.

Be sure the battery is a known good battery. If possible, test with another battery.

Review PQ5 which is the battery mosfet that should enable if on battery only; turn OFF if the power adapter is plugged in.

Yes, I checked these items and they were correct.
(two new battery tested)
(mosfet q6012 (switch between 19v and 11.5v battery)was ok.)

[mon2]

Re: Toshiba C75D no Power With Battery

Given that the unit fails to turn on if both the adapter and the battery are connected hints that you have a leaky mosfet in the power paths.

Post the resistance readings of the mosfets for a review.

Source & drain
Source & gate
Gate & drain

[ahkh_72]

Re: Toshiba C75D no Power With Battery

Given that the unit fails to turn on if both the adapter and the battery are connected hints that you have a leaky mosfet in the power paths.

Post the resistance readings of the mosfets for a review.

Source & drain
Source & gate
Gate & drain

I Pluged in AC and Battery and Measur points.

I marked the points I measured with a red line in the photo

[ahkh_72]

Re: Toshiba C75D no Power With Battery

Measurment With Just Battery.

[mon2]

Re: Toshiba C75D no Power With Battery

We were after the resistance and without power but the values look ok.

The gate voltage should be higher than the source/drain pins to enable which they are.

Remove the battery and confirm the resistance to be sure the mosfet is not always leaking (enabled).

Then review the same for the 2 x DCin mosfets.

The adapter detect voltage should be also > 2v4 to be considered as a valid voltage (usually is ~2v7).

[ahkh_72]

Re: Toshiba C75D no Power With Battery

We were after the resistance and without power but the values look ok.

The gate voltage should be higher than the source/drain pins to enable which they are.

Remove the battery and confirm the resistance to be sure the mosfet is not always leaking (enabled).

Then review the same for the 2 x DCin mosfets.

The adapter detect voltage should be also > 2v4 to be considered as a valid voltage (usually is ~2v7).

Measure without power .

[mon2]

Re: Toshiba C75D no Power With Battery

We are after the measurements across the mosfet pins.

One probe on source (1-2-3) and other on drain (5-6-7-8)

Then source & gate (4)
Then gate & drain

Post each measurement of each DCin mosfet.

[ahkh_72]

Re: Toshiba C75D no Power With Battery

We are after the measurements across the mosfet pins.

One probe on source (1-2-3) and other on drain (5-6-7-8)

Then source & gate (4)
Then gate & drain

Post each measurement of each DCin mosfet.

I chaged all (five) mosfet with new n-chanel mosfet.
and same result.

[ahkh_72]

Re: Toshiba C75D no Power With Battery

According to this post (https://www.badcaps.net/forum/showth...hlight=bq24725)

-It is exactly the same for me-

I think the problem is about non-orginal battery.

Tanks for your time #MON2.