Lenovo G40-80 ACLU3 ACLU4 NM A362 not charging

[G_sene]

That is fine but have you confirmed if the needle of the power adapter is present? Requested a pic and confirmation if the needle is bent or not.

I'll try to attach a photo. But it appears to be straight, without any damage.

[G_sene]

I'll try to attach a photo. But it appears to be straight, without any damage.

[mon2]

Looks good. What does the BIOS report about this power adapter? Most bioses will offer details of the power rating, etc.

[G_sene]

Looks good. What does the BIOS report about this power adapter? Most bioses will offer details of the power rating, etc.

This Lenovo's bios doesn't show anything about this.

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground of ADAPTER_ID. We are checking to see if PD304 is defective which will cause the analog voltage of ADAPTER_ID to be lower than normal.

[G_sene]

Remove all power. Meter in resistance mode. Measure the resistance to ground of ADAPTER_ID. We are checking to see if PD304 is defective which will cause the analog voltage of ADAPTER_ID to be lower than normal.

5.59k in ADAPATER_ID
Pin 3 of JDCIN1

[mon2]

What is the power rating of the adapter being used to power this unit? Did the same adapter function before to charge the laptop?

Review this thread:

https://www.badcaps.net/forum/troubl...esistor-values

[G_sene]

What is the power rating of the adapter being used to power this unit? Did the same adapter function before to charge the laptop?

Review this thread:

https://www.badcaps.net/forum/troubl...esistor-values

Model: PA-1900-72
20v - 4.5a
90w

I didn't ask if this charger was used before.
According to the customer, the laptop no longer turned on and was stored without working.

Another observation, when the charger is plugged in with the battery, it makes a ticking noise, it sounds a lot like a clock, something like that.

[mon2]

Go back to the DCin mosfets @ PQ301 / PQ302.

Remove all power. Meter in resistance mode.

Measure the resistance across:

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

Post each measurement for PQ301 and also PQ302. When powered from battery, the internal diode inside of PQ302 may conduct and present the voltage onto source pins (1-2-3) but this voltage should not be present on the drain pins (5-6-7-8) of PQ301 (with battery only as the power source). Both of these mosfets are suspects.

Update - Long thread. The above DCin mosfets are P-channel so if their gate voltage is lower than the voltage being passed through source / drain pins then yes, they will both enable ON. The gate voltage @ 5volts (confirm if still true) implies that the resistor based voltage dividers on the gate pins are active. We need to go back and study the mosfets that enable / disable these resistors. With only the battery installed, the gate voltage divider resistors on these P-channel mosfets should be disabled. Then the gate voltage, even if passing through the internal diode will disable these P-channel mosfets.

[G_sene]

Go back to the DCin mosfets @ PQ301 / PQ302.

Remove all power. Meter in resistance mode.

Measure the resistance across:

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

Post each measurement for PQ301 and also PQ302. When powered from battery, the internal diode inside of PQ302 may conduct and present the voltage onto source pins (1-2-3) but this voltage should not be present on the drain pins (5-6-7-8) of PQ301 (with battery only as the power source). Both of these mosfets are suspects.

Update - Long thread. The above DCin mosfets are P-channel so if their gate voltage is lower than the voltage being passed through source / drain pins then yes, they will both enable ON. The gate voltage @ 5volts (confirm if still true) implies that the resistor based voltage dividers on the gate pins are active. We need to go back and study the mosfets that enable / disable these resistors. With only the battery installed, the gate voltage divider resistors on these P-channel mosfets should be disabled. Then the gate voltage, even if passing through the internal diode will disable these P-channel mosfets..

PQ301

source (pin 1) - drain (pin 8) - 544k
source (pin 2) - drain (pin 7) - 543k
source (pin 3) - drain (pin 6) - 543k
source (pin 1, 2, 3) - gate (pin 4) - 200k
gate (pin 4) - drain (5, 6, 7, 8) - 343k


PQ302

source (pin 1) - drain (pin 8) - 1M
source (pin 2) - drain (pin 7) - 1M
source (pin 3) - drain (pin 6) - 1M
source (pin 1, 2, 3) - gate (pin 4) - 200k
gate (pin 4) - drain (5, 6, 7, 8) - 390k



Only with the battery plugged in, I still have 5v at the gate of PQ301 and PQ302.

[mon2]

What is the gate voltage with only the power adapter plugged in?

Does the gate voltage change if you have both, the power adapter & battery plugged in?

[G_sene]

I'll measure it again.

But before replacing the PQ303, it looked like this:

With charger and no battery:

PQ301 and PQ302

Pins 1, 2, and 3 = 20V

Pin 4 = 9V

Pins 5, 6, 7, and 8 = 20V

With battery and charger:

PQ301 and PQ302

Pins 1, 2, and 3 = 14V

Pins 4 = 5V

Pins 5, 6, 7, and 8 = 14V

Another detail: the 14V battery voltage reaches the charger input! I don't think this was supposed to happen.

[mon2]

If you have suitable replacement P-channel mosfets, replace PQ301.

[G_sene]

If you have suitable replacement P-channel mosfets, replace PQ301.

I replaced the PQ301 and it still doesn't work.
The charger isn't recognized, and the voltage on pin 1 of the jack is 14V.

Oh, I managed to test another charger with a lower amperage, but it wasn't identified either.
Bad battery?

Strange that it doesn't even identify the charger, and the computer remains connected only to the battery.

[mon2]

https://www.badcaps.net/forum/troubl...esistor-values

apply a resistor to ground on the adapter pin on the logic board and test again. Use a value close to the ones used by the poster of the above thread.

[G_sene]

https://www.badcaps.net/forum/troubl...esistor-values

apply a resistor to ground on the adapter pin on the logic board and test again. Use a value close to the ones used by the poster of the above thread.

It didn't work.
560 ohm resistor on pin 3 of the jack (ID pin) and the other terminal to ground.

[mon2]

Remove all power. Unplug the adapter from the wall. Measure the resistance between the center pin and the ground on the adapter cable. Want to know what resistance is on the id pin from the factory.

see here:
https://superuser.com/questions/1246...apter-slim-tip

[G_sene]

Remove all power. Unplug the adapter from the wall. Measure the resistance between the center pin and the ground on the adapter cable. Want to know what resistance is on the id pin from the factory.

see here:
https://superuser.com/questions/1246...apter-slim-tip

561ohm

[mon2]

Remove the extra resistor you have on the same adapter_ID pin since the power adapter has the 561 ohm value already.

Connect the power adapter to the board. Measure the voltage to ground on this adapter_ID pin on the logic board.

[G_sene]

Remove the extra resistor you have on the same adapter_ID pin since the power adapter has the 561 ohm value already.

Connect the power adapter to the board. Measure the voltage to ground on this adapter_ID pin on the logic board.

It had 1.44v before putting the extra resistor