Lenovo Yoga Slim 7 15ITL05

[Eniaro]

Vendor: SH
Board: GYG51 10D2

Water was spilt on the pc. Now will not charge or power on with USB-C PSU but still works on the battery
I do not know where to start looking for the problem, this is the first time I'm troubleshooting something with USB-C as it's PSU/Charger.

Nothing looks physically damaged except the Power switch led which will be replaced. It powers on with or without the switch assembly installed and with the Novo button when the switch assembly is disconnected but not with PSU

Does anyone know where I should be looking for the problem? I'm also looking for the schematics to see what I can figure out.

[tomodachi]

Re: Lenovo Yoga Slim 7 15ITL05

Difficult to diagnose a usb-c powered device without a usb-c ampermeter, obtain one first. Then post results so we can have an idea what to do and where to look.

[Eniaro]

Re: Lenovo Yoga Slim 7 15ITL05

I have a USB-C amp meter (see photo) but I had to purchase a coupler...

The amp meter flashes on and off rapidly when connected.

Update: The PC will only turn on if plugged into the JUC2 port with the battery connected.
And does nothing on the battery, without PSU connected to JUC2

PC will remain powered on, on battery if PSU is removed from JUC2 unless manually powered off. The charge light will flash for a brief moment, and while the charge light is on the USB-C meter drops to 5V 1A after which the charge light goes off and the USB-C meter displays 20.32V 0.00A

The PC will immediately power off if the battery is disconnected while PSU is still plugged into JUC2.



Powered off (connected to JUC2)
20.32V
0.00A

Powerd on (connected to JUC2)
20.32V
0.00A


Nothing happens on the primary charge port/JUC1 The USB-C meter flashes/power cycles rapidly.

[reformatt]

Re: Lenovo Yoga Slim 7 15ITL05

You need to lift up the black tape under the WIFI adaptor on the board and check for corrosion etc on UU1 and UU8. I fixed a Yoga a while back with liquid spillage in this area. It was a NM-D131 motherboard BTW and it looks the same as yours.

It wouldn't negotiate 20V if I recall. Cleaned up all the spillage in this area, and I reflowed UU1, UU3 and UU8 but no better. Before I went ordering IC's, I threw it in the ultrasonic which resolved the fault. Very likely crap was under UU1 me thinks as it's the PD controller.

[Eniaro]

Re: Lenovo Yoga Slim 7 15ITL05

Ran it through the ultrasonic cleaner and some progress was made

The laptop now powers on battery with no tricks, But still won't charge


Powered off (connected to JUC1)
5.01V
0.00A

Powerd on (connected to JUC1)
5.01V
0.00A

Powered off (connected to JUC2)
5.01V then 20.32V
0.00A

Powerd on (connected to JUC2)
5.01V then 20.32V
0.00A

Schematics can be found here