x360 15m-bp111dx Battery Not Charging

[drewrox2009]

computer had drop damage.
laptop does power on and boot into operating system.

battery + voltage is 11.8v when ac adapter not plugged in 11.45 when plugged in.

bq737 charge controller
1 acn 19.74
2 acp 19.74
3 cmpout 0
4 cmpin 0
5 acok 0
6 acdet 2.62
7 iout 0
8 sda 3.2
9 scl 260mv
10 ILim 200mv
11 ifault 147mv
12 srn 11.45
13 srp 11.46
14 gnd
15 lodrv 0
16 regn 6
17 btst 11.17
18 hidrv 11.46
19 phase 11.45
20 vcc 19.75

what looks out out of spec from my limited knowledge is scl being so low. and hidrv being same voltage as battery, no shorts on scl or hidrv.
another thing that is interesting is acok stays low even with power adapter disconnected.

with kbc "ene 9028g" being bga dont have direct access to measure pins. did reflow but did not reball or replace as i don't have the stencil. really stuck on this one.

[drewrox2009]

Re: x360 15m-bp111dx Battery Not Charging



did track scl and sda traces near kbc

[piernov]

Re: x360 15m-bp111dx Battery Not Charging

Check in diode mode to ground the SCL and SDA lines. Usually should be close value within 1%. If not probably broken line. As it is drop damage I'd guess the EC needs to be reballed.

The high-side gate is pulled to rail voltage to prevent spontaneous closing of the MOSFET so that current will never flow towards the battery rail. So the charger IC just never actually create the charging rail voltage because it never starts switching, so the battery never charges. Could be related to SCL if it requires communication from with the EC/battery to start charging.

[drewrox2009]

Re: x360 15m-bp111dx Battery Not Charging

Thank you for the response, i did check both in diode mode and resistance on scl line and sda line they were equal, don't have the measurements handy. I did reflow the ec hoping it would resolve any cracked or broken balls however i will order a stencil and reball the ec. I cannot find any great info on the ec. but if i were to replace it do you know if it needs to be programmed.

Last question, Do you know where i can purchase the correct stencils?

[mcplslg123]

Re: x360 15m-bp111dx Battery Not Charging

Thank you for the response, i did check both in diode mode and resistance on scl line and sda line they were equal, don't have the measurements handy. I did reflow the ec hoping it would resolve any cracked or broken balls however i will order a stencil and reball the ec. I cannot find any great info on the ec. but if i were to replace it do you know if it needs to be programmed.

Last question, Do you know where i can purchase the correct stencils?

Yes, 9028 kbc needs to be programmed. Aliexpress for stencils.

[drewrox2009]

Re: x360 15m-bp111dx Battery Not Charging

Stencils and ec ordered. i can't find what the bga configuration is on this chip, do you know which adapter i need for my programmer? haven't dug this deep into a kbc repair yet.

[drewrox2009]

Re: x360 15m-bp111dx Battery Not Charging

Thank you everyone for the help! Turns out it was this component pulling down the clock signal when it was enabled. Replaced with same component and charging is working correctly.