Sorry if this may seem obvious, but I thought I would toss it out there. Have you tried resetting the SMC? http://support.apple.com/kb/ht3964

I have the same question. Does anyone know the voltage readouts for the DC In board connector that leads to the motherboard? I want to verify that the board is putting out enough voltage and would rather not replace it if the problem is with the motherboard.

Starting in Step 10 there are very delicate connectors that are easily broken. I first attempted to lift one with a spudger and noticed it begin to crack. I found an alternative way that worked perfectly for all of these types of connectors. Using 2 straight pins, press the point of each one just on either side of the connector, between the connector and the housing. Then use each pin to evenly pry the connector up. It will pop right out of the socket with no damage.

I found that at this point I was able to avoid any further steps by removing the screw from the DC in board and the flip the machine over to reveal its connection to the board. I removed this connection and then was able to wiggle the board out and snake the cord out. Avoiding Step 38 saves a lot of screw removal. Not to mention not having to remove the CD Drive also saves a lot of time.

Just be careful when doing this that you do not force the board out of its place. There is room to remove it, but it is a gentle task.

On a Macbook I just tore down, I found that in this step, the 4mm screw was on the left, not the right. I thought maybe someone else had it apart before and accidentally switched them so in staying true to these instructions I tried to reassemble with the 4mm screw on the right. I found it would not go all the way in. I ended up putting it back together with the 2-3mm screws on the right and the 1-4mm screw on the left.