I suspect it is overheating and has damaged some or part of anything touching the motherboard.
What I mean is that there may be issues with cpu and or ram also.
That would be cost over and above the motherboard.
Politly, you DO NOT want to start that project.
Funny thing about laptops, they have very thin wire and wireruns on plastic.
Short answer is most non-experts that work on their laptop useually wind up with an expensive door-stop.
I know this is not what you want to hear.
it is ,however, what you need to hear.
What you need to do is see what the laptop is worth, worth to you.
400+200 to put it in=$600
That puts you at the begining of new laptops or a nice refurb from dell-hint hint
