HP Probook 430 G2 (LA-B171P) Battery not detected

[RomanSko1]

First of all I want to thank you all guys for such a great support. Nice community!!!
This stimulates me fix the issue myself.
Here is what I have by now.
I found another manual - la-b181p. All labels fit my motherboard.
1) I tested 2 diode suppressors (d3901). They are perfect. I even unsoldered them to test if smth changes but ... no!!!
2) I also tested all resistors involved: 100 ohms; 4.7kohm. Everything is fine as well as capacitors.

I like the idea to cut pin 111 from MEC1322. But that's a risky procedure. Will this trick work if I unsolder BQ?

And one more question. If I replace MEC do I have to flash smth? Should I backup bios?

[mon2]

As per post # 18 suggestions:

1) disconnect the battery. Meter in DC volts mode. Measure the voltage of the battery between pin # 1 (ground) & pin 6 (+) while the battery is disconnected from the logic board. Need to know the current voltage on the battery. It should be ~13 volts.

2) Now connect back to the logic board -> the battery voltage drops to ~2 volts ? Confirm this important detail.

The battery is confirmed to be compatible with this logic board? So the same connector pinout ? You may have a low side leaky mosfet on the charger circuit.

[RomanSko1]

1) The battery shows 0v when it is disconnected.
But I should mention that the battery was tested on the same laptop (my friends') and it was detected and charged.
When I insert it into mine it is not detected but it powers my laptop well until not discharged.
So, i'm sure it gives necessary voltage. The problem is not on the battery side. I checked 4 more new batteries from local seller. None of them is detected.
2) When i connect battery back to motherboard the voltage drops to 2.5v.

I tested the battery using arduino. It communicates fine via smbus. Pinout is absolutely the same.

[mon2]

If the battery voltage drops to 2.5v, it cannot power the logic board. Can you confirm the main power rail voltage? The laptop operates fine using only the battery as the power source?

[RomanSko1]

If the battery voltage drops to 2.5v, it cannot power the logic board. Can you confirm the main power rail voltage? The laptop operates fine using only the battery as the power source?

The laptop operates perfect when powered by battery.
But now I can't charge battery, cause it is not detected.
The voltage becomes 13v after i press on button. But now it is impossible cause I disassembled motherboard and the voltage of the battery became too low .
I become more and more convinced about MEC problem (((.

[mon2]

Based on the shared information and the feedback from the other techs, the MEC (microcontroller based) could be defective or the internal firmware is corrupted. The battery BMS communicates over SMBUS / I2C which you have confirmed is not defective. Usually there should be only a single SMBUS master and that is the charger IC. However, since the same SCL / SDA lines also travel to the MEC, if the MEC GPIO pins are not properly configured (they are not defective based on the posted diode mode readings), they SCL / SDA lines maybe strapped or at least preventing the SMBUS traffic from proceeding -> resulting in the failure to detect the battery pack.

If your arduino can be made to act like a SMBUS analyzer, you can confirm this theory. Monitor the traffic while booting the logic board. Personally, would hunt down a nearby trace near the MEC pins and with a sharp X-ACTO knife, cut the PCB trace. Later, you can scrape off the black / blue / whatever color solder mask and solder blob it back together again. This idea is to only remove the MEC from camping onto the suspected SMBUS interface. At this time, we really do not know if it is ONLY the SCL or perhaps could be both, the SCL and SDA lines that are being messed with by the MEC.

Suggest to start with cutting a small PCB trace on the SCL line only -> test. Just the same, what role is the MEC playing here with the battery?

[RomanSko1]

I've unsoldered mec and now sda pin is 3.3v.
So, i am waiting for a new mec1322-nu.

[mcplslg123]

I've unsoldered mec and now sda pin is 3.3v.
So, i am waiting for a new mec1322-nu.

Whenever any member see SDA/SCL dropping down and it have a MEC SIO, first doubt should go there. This i'm telling from hard experience. Btw, I'm not sure whether MEC1322 is programmable or not. Hope other can confirm it.

[RomanSko1]

As far as I understood it's not programmable.

https://www.badcaps.net/forum/troubl...mable-sio-list

[RomanSko1]

Hi, guys!!! I finally received my new MEC from china!
Installed it and ... BINGO!!!! It works!!!
Battery detected and charged!
Thank you all for your help!!! 🙏 🙏

[RomanSko1]

I was celebrating too early.
Found an issue 😕.
When i unplug AC adapter the fan starts working at 100% and after reboot bios error 90b appears. (((
If i plug in charger everything is fine.
So, battery usage leads to incorrect fan work.
I checked mec pins several times if they are soldered properly. Everything is perfect.
What can be the reason?

[mcplslg123]

Bad MEC chip. You know the chinese stuff.

[mon2]

Reflash your bios with the latest and greatest version.