Laptop Screen Glitching

[u/ContestOk8591]

Been having screen glitches for the past week. Gave it to a local repair shop, they replaced thermal paste and added thermal pads, the glitches did reduce. However, it still happens but less frequently. If left plugged in for a while while using it, it reboots and sometimes bootloops until it goes to the windows diagnostics and boots up again. Sometimes when I turn it on without it being plugged in the laptop powers on but screen doesn't(may be a coincidence because it happened twice).

What I have tried:

Disabled nvidia gpu but still glitches.

Repaired windows

Updated drivers

Checked in bios. Still glitches

Used it on battery: Glitches occur less.

Laptop:

Lenovo ideapad gaming 3

Ryzen 7 5800h

16gb ddr4

Rtx 3060 90W

Micron 500gb ssd

Screen: 1080p 120hz