lenovo yoga 13 2191 no turning on

[questore]

Re: lenovo yoga 13 2191 no turning on

37k on Vcc is too high. Yes 10 ohm sounds correct. Also inspect the dual diode on your logic board if present that feeds this rail.

Thank you for confirming my theory.
Before The 37kOhm Resistor the voltage is perfect 20.0v. So I am assuming the diode is fine, but i will check.

[questore]

Re: lenovo yoga 13 2191 no turning on

After replacing the resistor to 10Ohm the following values are present on charger chip (values without battery only AC adapter):
NOTE : 8150L chip is still not in place since I'm waiting for it. It is possible that ACOK is missing cause the 3.3v is not yet present and pullup resistor cant pull it up.

1 ACN - 20v
2 ACP - 20v
3 CMSRC - 20v
4 ACDRV - 25,5v
5 ACOK- 0v
6 ACDET - 2,75v
7 IOUT - 0v
8 SDA - 0v
9 SCL - 0v
10 ILIM - 0v
11 BATDRV - 2,87v
12 SRN - 2,85v
13 SRP - 2,85v
14 - GND
15 LODRV - 0v
16 REGN - 6v
17 BSTR - 5,87v
18 HIDRV - 2,85v
19 PHASE - 2,85v
20 VCC - 19,8v

Post the vaules after 8150L is replaced.

[questore]

Re: lenovo yoga 13 2191 no turning on

Changed 8150L
Now I have 3.3v and 5v
ACOK is still 0v.
BQ735 values not changed
Any ideas?

[questore]

Re: lenovo yoga 13 2191 no turning on

one of the previously posted link now makes sense:
https://www.elvikom.pl/lenovo-yoga-1...ad-t53251.html
Since my 3.3v and 5v rail is not working but not have a 3v on the KBC line i should replace the KBC IT8519G.see you in 30 days when result comes

[questore]

Re: lenovo yoga 13 2191 no turning on

Replaced ITE chip. still no 3.3v. Resistance risen to 6 Ohms.
the Charger chip has 0.6v on AC_ON.
I wont waste more time on this.
Project abandoned.

[questore]

Re: lenovo yoga 13 2191 no turning on

I decided to keep working since I have some time ti kill and I'm curious.
Found a page with the main components numbering:

SR0XL + SLJ8B
IT8519G
BQ735, ISL95831, ISL8014A,
25Q64CVSIG, 25X20BLIG

[questore]

Re: lenovo yoga 13 2191 no turning on

End of project,
Made a rookie mistake and left the battery connected in the meantime and it seems the whole 3v rail is gone now. Shorted every capacitor in the line and after removing them all the SIO is sorted
Project End

[questore]

Re: lenovo yoga 13 2191 no turning on

More info for somebody who will face the same problem:
Ordered a new motherboard :
The resistance in the 3V line of the SIO is 148 KOhms in a working board.