Lenovo legion 7 16achg6 board repair

[Erikas Tarvydas]

Hello,

I have a Lenovo Legion 7 with the following specs:

• RTX 3080
• Ryzen 9 5900HX

A problem started suddenly overnight. The next morning, the laptop wouldn't boot properly — the RGB lighting on keyboard turned on, fans spun for a brief moment, but the screen remained black, and the Caps Lock key didn't respond (no indicator light).
When running on battery power, the laptop would stay in this state for about 35 seconds before automatically shutting off. When plugged into AC power, it would keep restarting every 35 seconds. Holding the power button would shut it down, but it would immediately power back on by itself (only when plugged in).
While attempting to diagnose and measure voltages, I accidentally shorted something with a wire that had fallen off my workbench — I couldn't see exactly what was affected and no obvious burnt components are vissible.
After this incident, the behaviour changed: the laptop no longer restarts as before, and it now reacts the same way whether it's on battery or plugged in. Upon pressing the power button, only the led's on the back turn on (no RGB or display), and holding the power button now properly turns it off.
I have also not been able to find direct short nor on power lines nor on cpu and 3.3V, 1.8V is present but there is no voltage on cpu and gpu (before it was arround 0.8V).

Any guidance or suggestions on how to proceed would be greatly appreciated.
PS I can't upload a photo of where the wire shorted something due to error "Upload failed due to failure writing temporary file."

[SMDFlea]

try to upload your pictures again

[Erikas Tarvydas]

Thank you! Here are the photos. The red markings indicate the approximate area of contact with the wire. Although I smelled something burning, I couldn't identify any visibly damaged components.
PS I have the boardview files if needed. Please help

[ktmmotocross]

at first u have bad PCH in cpu or cold joint under cpu, thats why PCH dont respond to starting signal from SIO and SIO not start S3/S4. It is not repairable as Lenovo underglue cpu.

that other fault of yours is just bonus

90% of legions dies because of this

[Erikas Tarvydas]

Hmm, okay. But would it be possible to reball or even solder on a new CPU? I’ve seen people do GPU core reballs and similar stuff. Also, sorry if this is a dumb question, but is the PCH integrated into these Ryzen CPUs? And if I understand correctly, SIO and S3/S4 refer to power rails? Apologies again for the beginner questions — I’m still trying to learn the terminology.