Sleepy computer

My Problem

My computer (cir. 2007 macbook, 2.16 core duo, 4 gig ram) has been going to sleep (?) and not waking up. I have been trying to figure out why. It seemed to work without the hard drive in the computer but being read from an external hard drive reader. I thought, just maybe it was a bad SATA cable. It turns out it still goes to sleep with the new SATA cable in it, so that was not the problem...

My Fix

Repair was easy, guide was accurate.

My Advice

Easy to do, just keep track of the screws and have the right tools for the job!