Could I have damaged the logic board here?

I just sold a 13" MacBook off Craigslist to a woman who seemed to know at least a little about Macs. It was in absolute perfect working order for months before the sale. Now, three days later, she sends me an e-mail saying the screen has gone black and the Apple Store told her the logic board needs replaced. How is this possible?!? The only hardware changes I made to it were a Ram upgrade and I switched out the 80GB hard drive, both of which worked flawless before I sold it to her. So my question is: would either of these things have damaged the logic board so badly?

Who cares? You don't own the laptop anymore and you are not responsible for the unit after the sale.

There is not a chance she pressed the key to dim the display is there? I know on my iBook G4 you can turn it completely off and it's black unless I press the other key to turn it back on and up in brightness.

I'd say it's BS. 3 days later she's already set up an appointment at the Apple store and had them test it out? Not likely. More likely, the one the Apple store looked at is not the same one you sold her.

You guys are absolutely right. It was working when I sold it so the deal's done.

Still, just curious: Could the switching out of the hard drive damaged the logic board, let alone touch it?

I really doubt it. The Hard Drive in the Macbook is a user replaceable part. Only thing I could see you doing is bending pins on the drive if you put it in upside down or something or at an angle. But it worked after you put in the drive so you did nothing wrong as far as I am concerned.

Keep us posted on the situation.

What does it take to damage the logic board anyway?

Power Surge, Static, Liquid spilled on the notebook. You took out the battery and took out the 3 screws and slid out the hard drive correct? If you did it that way I see no way you can kill the logic board.