HP ELITE X2 1013 G3 weird battery issue

[rediii]

check the two pull-up resistors in between the lines, maybe one is faulty. normally they measure the same (datasheet says 10k).

[huzo]

There are none of the pullup resistors from any side...i have some bad pictures, i won't even upload them, but there are none on this line...i've connected the wire directly to the pins, but still nothing...

[mon2]

Hunt for TVS diodes on the smbus lines used by the battery. Flux and remove the tvs diodes.

Remove all power. Measure the resistance from the sda line at the battery connection directly to the ISL charger ic pin of the same net name. What is the resistance?

Repeat for the SCL line. There may be a disconnect in one of the smbus lines.

[huzo]

.i've connected the wire directly to the pins, but still nothing...

SCL from controller to the battery connector is now directly connected, now i have 3.46V at the connector on both pins , but still nothing, havent find anything on the line on SCL, no resistors,diodes,nothing...that pin go directly through the hole to the other side and connect to the test points and to the controller ,no components are connected to the line...I havent measure the resistance,only in diode mode, i get 0.500 in diode mode on both pins...

[mon2]

3v42 / 3v46 are odd pull up voltage values.

Carefully measure and post each voltage to ground on the charger IC (ISL9238). Also post their pin # and function for an easier review of the measurements.

[huzo]

But i did alreadey....3.46V on both SDA and CLK on the chip and on the connector

[mon2]

No, I meant the rest of the charger IC pins. To me, this pull-up voltage is not normal. For SMBUS / I2C, there will be SMBUS slaves and usually a single bus master. Every participant must operate or tolerate the voltage swing for the SCL / SDA lines. The rather high voltage of 3v42 / 3v46 is not normal and expected this to be 3v3. On this note, do you see the presence of the same voltage on other parts of the board? Check parts like the flash IC (Vcc pin), etc. Someone is creating this pull-up voltage and it may be from the ISL charger chip itself (much like REGN is to the BQ series chips which is used for ACOK, etc.).

Perhaps extreme but you can attempt experiments using Arduino or similar to ping the same battery to confirm the SMBUS interface is functioning correctly. The best tool here would be a logic analyzer which will snoop the SMBUS traffic that is being transferred between the SMBUS master and slaves. The battery BMS will have its own bus address and using this as a trigger, you can log the data traffic for a review.

[huzo]

Oh now i get it...you think 3.3V is no good...I do see that SCL and SDA operate on exactly 3.3V...ok, i will try do measure 3.3V on the rest of the board..... Regarding Arduino, i do have an empty board somewhere, do you have the script for it maybe?,the analyzer that you mentioned?

so i've raken the measure...i get 3.46V on the battery at the 3.3V BIOS pin 8 and everywhere on the board i could find , and 5.2V at the 5V coil... When running on the charger only i get 3.38V and rising...BUT, i was searching what is generating 3.3V and found the coil under the metal shield, and as i removed the shield , the volrtage went to exactly 3.3V and now i get stable 3.3V everywhere...my insturment is ok, beacuse i've checked it on my excternal PSU Pictures ffrom measuring on battery , and only on charger, and referencing voltage on my External PSU


But still not working...The voltages around 9238H are all in range referencing to data sheet...

[huzo]

Another odd thing is, when no battery is connected it says the same, that the battery capacity is getting low and should be replaced, but no battery is connected...

[mon2]

Locate pin #17 on this isl9238 charger ic (dcin).

There will be a dual common cathode diode. Flux and replace this part.

reference:
https://www.renesas.com/en/document/...uide?r=1167746

[huzo]

there are two seperate diodes...the pin 17 on the controller goes to the cap and 100Ohm resistor,then the line goes to the other side of the board to the two diodes

[mon2]

Since we do not have a schematic, the reference schematic was only that, a reference. The separate diodes will accomplish the same goal of powering from the battery or external power adapter.

Remove all power. Meter in diode mode. Measure each of these diodes in diode mode. The diode must conduct in one direction and block in the opposite when the meter leads are reversed.

If you see conduction in both directions, flux and replace that diode. In the past, the observed fault was due to this region of the board on the charger IC.

[huzo]

Remove all power. Meter in diode mode. Measure each of these diodes in diode mode. The diode must conduct in one direction and block in the opposite when the meter leads are reversed.

.

I know that, and i tested that already... i am not that novice So we have SDA and CLK to the 9238h, All the pins are present, battery is charging and depleting, but the meter shows 0%

[mon2]

Each post is often written so any newcomer can read it and follow through on the trouble shooting.

The raised question was not answered.

[huzo]

for all the newcomers, both diodes measure 0.580 in diode mode.... i have checked the pin 17 with battery voltage when on battery and adapter voltage when on power adapter,pin 18 also,pin 19 is 5V,pins 21 and 22 are around 3.45V, pin 26 has the resistor 100k and 2,8V ,that's ok,31 and 32 are on mosfet G and D and that's ok, other ugate and phase are working since the battery is charging...what else to look?

[mon2]

For the 'pro bros'..

[huzo]

I don't think that part is connected to the circuit,but there you go...the resistor is droping from 180-125Kohm... probably chartging some cap and it reduces the resistance... Diode leads don't connect to that transistor,or whatever it is...it's anodes go to one another...

[mon2]

the pin 17 on the controller goes to the cap and 100Ohm resistor

Can you confirm the 100 ohms again? It sounds rather high. This should be at 1-10 ohms and should follow the dual diodes.

[huzo]

Sorry,not 100, 10Ohm, i had an excess zero...

[mon2]

Disconnect the battery. Attach only the power adapter. What is the voltage to ground of VBAT (pin # 31) on the charger IC?