I had a pleasure of replacing a CPU on an Acer laptop. It refused to work. I have it on video, 3 or 5 minutes after boot (can’t remember, but it was consistent) it would shut down.

Later, i found out that even though you can replace the CPU in that laptop, Intel has made it so that if that unit wasn’t configured with that CPU when you bought it, it would simply shut down after X minutes.

Can’t recall the name for that “feature” unfortunately.