@daradean
He's correct about the cost of replacing a motherboard -- in that it can easily cost as much as simply replacing the laptop.
We can't tell you if that is the issue because we have no way to access or diagnose your laptop from here.
I don't know what you mean by having the BIOS "restarted". You would have to explain what that means if you want our comments on that.
I am a volunteer and I do not work for, nor represent, HP