hi every one i need some help with lenovo x140e

[amr soliman]

the laptop came from another shop dead
it was caps short now it works but not charging
mb DALI2KMB8D0 REV D

[mon2]

Re: hi every one i need some help with lenovo x140e

Is the battery detected in Windows ? Does the Windows OS show the charging symbol ?

See attached.

1) Meter in DC volts mode (20V or higher).

2) Check the battery voltage at the battery connector pin # 6 & 7.

3) Check for the same voltage reading AFTER the fuse @ PF1 pin # 1. Same ?

4) Check the voltage on the battery SMBUS communication lines.

These are pins # 4 & 5 on the battery connector.

What are the voltage readings for each pin ?

5) If the voltage on the SMBUS pins is not ~3 volts for each, then remove all power. Remove the battery.

Meter now in resistance mode.

Check the resistance to ground for each SMBUS interface pins. Checking to see if the SMBUS pins are stuck low / damaged.

Post the resistance readings.

[amr soliman]

Re: hi every one i need some help with lenovo x140e

THX FOR FAST RESPOND
its pluged in not charging
pf1 is ok
cn14 pin 4&5 3.3v
pin 3 3,3v withou batt 1.6v with batt
pin 6&7 1.053v without batt 11.5v with batt

[mon2]

Re: hi every one i need some help with lenovo x140e

How old is the battery ? Is the battery to be a known good battery ?

[amr soliman]

Re: hi every one i need some help with lenovo x140e

the battery is good
and its charging on another laptop

[mon2]

Re: hi every one i need some help with lenovo x140e

Ok. Does the Windows OS detect the battery ok ?

Does the battery graphics in Windows show the charging symbol ?

You seem to have a dead battery, does Windows show 0% or similar since it is dead ?

On this note, if you use the other laptop to charge up this battery and return to this logic board, does Windows show that the battery is charged UP ?

Respectively, if the battery is not present, the Windows OS shows the battery is missing ?

These tests confirm that the SMBUS (I2C SDA / SCL) lines are working and communicating with the host and can extract information from the BMS (battery management system) module inside the battery pack. The BMS holds the serial #, # of charge cycles, etc.


Next to inspect will be the mosfets linked to the battery circuit.

These mosfets are PQ40, PQ41 and PQ1.

Start with attaching the battery, meter in voltage mode:

1) What is the voltage on the gate pin # 4 of PQ40 ? (High Side battery mosfet)

2) What is the voltage on the gate pin # 4 of PQ41 ? (Low Side battery mosfet)

Next, remove all power & battery to perform a resistance check on the same mosfets.

Meter in resistance mode (start with the lowest scale) - if you read '1' or 'OL' (over limit) then switch to the next scale in the meter:

Check the resistance across the mosfets pins as follows:

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


What are the resistance readings for the above for PQ40 ?

Repeat for PQ41.

[amr soliman]

Re: hi every one i need some help with lenovo x140e

the battery is 73% pluged in not charging and battery icon shown in windows bar and shown that adapter is connected but not charging

[amr soliman]

Re: hi every one i need some help with lenovo x140e

i'll take measurement and let you know

[amr soliman]

Re: hi every one i need some help with lenovo x140e

pq40 pin 4 11.5v batt connected
pq41 pin 4 0v batt connected

[SMDFlea]

Re: hi every one i need some help with lenovo x140e

pq40 pin 4 11.5v batt connected
pq41 pin 4 0v batt connected

Test voltage on ACDC_ID

[amr soliman]

Re: hi every one i need some help with lenovo x140e

sorry for late
acdc_id is 3.23v

[mon2]

Re: hi every one i need some help with lenovo x140e

I think @SMDFlea has nailed it with the ACDC_ID request.

This is a simple voltage divider circuit that Lenovo uses to announce the power of the AC adapter using an external resistor.

Based on your feedback, this ACDC_ID pin is ~3v23 volts ?

This implies the external adapter resistor is not even seen by the logic board.

What is the marked power rating on the Lenovo adapter ?

Next, see the post with details here from other seasoned pros on the forum:

https://www.badcaps.net/forum/showthread.php?p=844161

Specifically:

Originally Posted by Th3_uN1Qu3 View Post
Hello, as you know, for Lenovo laptop, the AC adapters have an identification pin. They use a simple system with a resistor to ground from the ID pin.

Here are some values for the resistors:
65W adapter: 270 ohms
45W adapter: 116.5 ohms (you can use 120)

We had a T450s in with trouble recognizing adapter, due to poor quality power jack (not broken, just poor quality). Tried 3 adapters and it was hit and miss on all of them. I have disconnected the ID pin from the connector that plugs in the motherboard, and soldered a 270 ohm resistor from the connection of the ID pin to ground. Now any adapter plugged in is recognized as 65W, no problem charging the battery now.

Based on this lack of external resistor not being found, the logic board then decided for you that the battery cannot be charged as the AC adapter is too wimpy to perform this task.

Proceed to review the markings on the adapter to confirm the power and then consider to solder in a 270 ohm resistor to ground on the AC adapter pin # 5 (CN15) on the logic board.

So this means that the logic board will see 270 ohms + 220 ohms (PR171) to ground to announce that you are using an external power adapter @ 65W.

Review it and post your updates.