Watch the cable next to where the battery plugs in

Mon problème

Battery was out completely, swapped it out with a new iFixit battery.

Ma solution

Once swapped the computer did not turn on. After a day of stress, found that the problem was the small connector left of where the battery plugs in. It had come loose slightly. With tape, nudged it back in to position. This is the only thing to be aware since the battery touches this cable.

Mon conseil

Again, if the the computer does not turn on, check that cable. Also be careful with stripping the screws.