Lenovo G485 LA-8681p Laptop recognized charger only when OFF position

[julianmustofa]

Hi i've been troubleshooting laptop that only charge/recognized dc in when it in OFF position.
When i plugged in charger in ON position it won't recognized/charging at all
So when i need to charge the laptop i need to turn it off>plugged charger>and turn it on again. That way the laptop is charging/detect dc in
I have an schematic of the board. But i'am not expert at diagnosing board level like this
So what i need to check in this kind of problem? Is it resistors? Or mosfet charging?

I provide the schematic link thanks
Schematics: https://drive.google.com/file/d/1Akh...rKK-Y7Sl8/view

[mon2]

Re: Laptop recognized charger only when OFF position

The square box in the schematic is the battery charger IC by Texas Instruments under the name of 'BQ'.

This chip decides when to charge and how to charge the battery.

You will need a multimeter to carefully measure each pin on this charger IC with the adapter and battery connected. With a steady hand so the pins are not shorted.

Meter in dc volts scale of 30v or higher. Red probe to the pin. Black probe to ground on the laptop. Shield is ok.

Post the voltage readings and each pin number when ready.

[Vesko356]

Re: Laptop recognized charger only when OFF position

Hi i’ve been troubleshooting laptop...

Add full device model name to the request and thread title.
All schematics must be uploaded at Schematic Requests section, but first look (use forum search engine) to see if someone has already uploaded it:
https://www.badcaps.net/forum/forumdisplay.php?f=41
Then you can add link to the pdf file you've uploaded there in your request.
Links to external websites for download are not allowed, you must upload the file(s) here at the corresponding section of the forum as I already mentioned above.

[julianmustofa]

Re: Laptop recognized charger only when OFF position

The square box in the schematic is the battery charger IC by Texas Instruments under the name of 'BQ'.

This chip decides when to charge and how to charge the battery.

You will need a multimeter to carefully measure each pin on this charger IC with the adapter and battery connected. With a steady hand so the pins are not shorted.

Meter in dc volts scale of 30v or higher. Red probe to the pin. Black probe to ground on the laptop. Shield is ok.

Post the voltage readings and each pin number when ready.

In the way measuring the charging ic, i notice that mosfet PQ302 was hot when i plugged in the charger. I try to replace that mosfet and now its charging normaly even when laptop ON position.
Btw huge Thanks for advice