How can I determine why my MacBook will not boot?

Thanks so much. Booted up right away. Guess I'm in for a new topcase. Don't really mind, much cheaper than a logic board.

Thanks again,

Nathan

I am at a loss to know why you recommended that procedure. I would never have done that. Would you tell why? + vote for being right

Just wondering, mayer, did you know about this "jump start"? I've never heard of it at all before, and find it fascinating. It can definitely help rule out or determine a faulty top case. I guess there's a possibility of frying the whole logic board, but I was willing to take that risk. Also, to clarify, I shorted the board where the top case connects to the board itself. I was not able to see a power logo, and although it was very risky, I just started making somewhat random connections, in an attempt to boot the computer.

To mayer: why I recommend this procedure ? Because if you don't have a known working top case as spare part to troubleshoot the macbook it's the usual way a tech will determine if the top case is in trouble or not. Why do you think these two power solder pads are available and identified on the logic board ? Why not recommend this procedure ? The OP already said he tried SMC without result and has no power reaching the logic board so IMHO I think it's the adequate procedure for his specific issue. Now if the OP thinks the procedure is too hazardous he can ask a tech to do it for him but others users here can use the procedure and save the price of a logic board replacement.

In my case, it wasn't really identified. I couldn't find them.