Lenovo S145-15IL won,t charge

[Zippo978]

Hi everyone,
I have a Lenovo motherboard Lenovo S145-15IL, NM-C711.
Initially it wouldn't turn on, I replaced the PQ100 and PQ101 mosfets and the BIOS chip and it works perfectly except charging the battery which says it's connected and charging but the percentage doesn't go up. In pins 1 and 2 of the JBATT5201 I find 7.8V, and at the input of the PQ102 and 103 mosfets I have 19V.

I don't understand why the battery doesn't charge, thanks in advance for your help.

P:S: Thinking it was the battery I replaced it with a new one and updated the BIOS and Firmware.

[MOD EDIT] Link to schematic https://www.badcaps.net/forum/troubl...atic-boardview

[mon2]

Share each voltage on the battery connector. We wish to confirm the smbus voltages for the sda / scl lines. Every such battery pack counts a bms (battery management system) that communicates over smbus to the charger IC.

Be sure the batteries and the power adapter are compatible for this unit. If the power adapter is under rated, the battery will not charge.

[Zippo978]

The charger is original Lenovo and has 20.42V output

The battery is compatible, I had already replaced the original with the same model and it worked perfectly.

The voltages on the battery connector are

Pin 1/2 - 7.82V (VBAT)
Pin 3 - ranges from 3.25V to 3.29V (EC_SMCA)
Pin 4 - ranges from 3.25V to 3.29V (EC_SMDA)
Pin 5 - 1.26V (N17245833)
Pin 6 - N/C
Pin 7/8/9/10 - GND


If I put the original battery it says 100% but that's not true.

[mon2]

Remove all power. Meter in lowest resistance mode.

Measure the resistance directly at the charger IC pin # 11 to the actual battery connector (disconnect the battery during this measurement). Confirm there is a full path from the charger IC to the battery connector. What is the resistance?

Repeat for pin # 12 in the same way. What is the resistance?

Confirming that the SMBUS lines have a valid path from start/finish.

The charger IC is 'assuming' the battery capacity because it is reading 'FFh' default values.

[Zippo978]

If I understand correctly, I have to measure from pin 11 and 12 of the PU100 to pin 3 and 4 of the battery connector, right?

From the battery Pin 3 - pin 11 4.49k pin 3 - pin 12 0.10k
Pin 4 - pin 11 0.10k and pin 4 - pin 12 4.49k

[mon2]

These measurements are ok. This confirms the PCB traces are ok from start to finish with 100 ohms of resistance as showing in the schematics.

Locate pin # 5 on the battery connector and connect it to ground.

This is the BATPRES# signal and is active low (denoted with the '#' suffix). If this line is a logic LOW = '0' then the battery is present. Then test again. Post your updates.

[Zippo978]

So with the battery inserted I measure from pin 5 to ground and redo the first measurements right?

Sorry but I just started.

[mon2]

Also interested in the resistance reading (measure directly at the charge IC) of pins 19 & 20. One probe on 19, other on pin 20 - no power / no battery during this measurement. We are checking the full path resistance of the current sense loop circuit for the battery charge circuit. This measurement should be ~20 ohms if all is ok.

[mon2]

On post #7 - no. Take a piece of wire and connect one side to ground - the other side of the wire to pin # 5 of the battery connector. We are forcing this pin to ge at 0 volts which is ideal to force the charger to know there is a battery connected. Then test again. The wire must remain in place as noted to ground.

[Zippo978]

From the battery Pin 3 - pin 11 4.44k pin 3 - pin 12 0.98k
Pin 4 - pin 11 0.09k and pin 4 - pin 12 4.44k

[Zippo978]

Also interested in the resistance reading (measure directly at the charge IC) of pins 19 & 20. One probe on 19, other on pin 20 - no power / no battery during this measurement. We are checking the full path resistance of the current sense loop circuit for the battery charge circuit. This measurement should be ~20 ohms if all is ok.

20Ohm

[mon2]

Post a pic of your meter screen to confirm the units of measurement. Also touch your meter probes together while in the resistance mode. What is the measurement?

See attached on how to short the wire on pin # 5 of the battery connector = BATTPRES# signal.

[Zippo978]

Sì, i fili sono stati tagliati, il connettore è stato preso da una vecchia batteria danneggiata e invece di saldare ho legato insieme un filo di terra e il filo del pin 5



I have a automatic tester

[mon2]

Ok. With the power adapter and battery connected -> carefully measure the voltage to ground at inductor PL100. This is the battery charge voltage.

[Zippo978]

Ok, 7.8V

[mon2]

What are the battery pack markings for the voltage?

What is the voltage to ground of ILIM pin # 21 on the charger IC ? This pin defines the battery charge current.

[Zippo978]

ILIM 1,182 V

Bbatteria originale



Compèatible

[mon2]

While the battery is not connected to your board - what is the voltage? Measure between the RED and BLACK wires on your battery pack. It appears that the charger IC is not even producing the charge voltage. The voltate you are measuring is from the pre-charged battery itself. Confirm it.

[Zippo978]

On the battery I have 7.3V


I have to go now, we will continue tomorrow, thank you for what you have done so far

[mon2]

Ok. It appears that the high and low side mosfets are not creating the charge voltage to charge the battery pack.

Tomorrow, test PQ103 and PQ104 by their resistance. Remove the battery & power adapter.

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)

Interested to know each resistance measurement. Do this for both mosfets. If either mosfet is defective, the battery will not charge.