It is very unlikely you would need to change the motherboard, just because you were getting blue screens, there are many reported problems with Nvidia drivers and that is the usual cause.
Please check to see if your laptop is producing any minidump files, I will check those to see if they provide any insight into a potential cause of the system crashes.
Please do not upload a very large Memory.dmp file.
Open Windows File Explorer.
Navigate to C:\Windows\Minidump
Copy any minidump files onto your Desktop, then zip those up.
Upload the zip file to the Cloud (OneDrive... etc.), then choose to share those and get a share link.
Then post the link here to the zip file, so I can take a look for you.