MacBook Air won't boot with full battery, unless additional "2 min" kick-start adapter charge.

Thanks for your reply, but I have some more info to add:

When I wrote the original post, this was the situation. I used the laptop with no problems for many months. Now this problem occured twice since only three days. Today it hapened again. Thus, perhaps it can be further isolated.

First time the battery was 90% charged, and it did boot after several minutes of connecting the adapter.

Second time the battery was 20% charged, and it did boot after several minutes of connecting the adapter.

Today it was different. This night I left my MacBook Air charging so it must have been at 100% this morning (adapter light was also green). However, this morning it won't boot, and the 'connect it to the adapter trick' doesn't work!

1- perhaps internally the laptop switches from battery to net-power after a few minutes of charging if not fully charged, and if this does not happen my power button doesn't function? Is there more info on the logic/internals related to this?

2- less logical (no pattern yet): the power button does not work if the laptop believes the screen to be closed?

Many thanks!

I kindof did it, and I bet you even a Genius wouldn't have figured this one out!

What did I do? Well I checked everything: opened up the macbook, measured power going in, measured power reaching battery, measured battery giving charge back, measured power going through logic board and, finally, tried power-on skipping the keyboard/mouse by connecting the power-on pads on the logic board - but it did not boot!

So my logic: 1) somewhere on a very elementary level something is broken that prevents a power-on between the power-on pads and whatever is next. 2) this broken thing was temporarily fixed twice when I was able to charge my battery for several minutes, as if things were 'heated up a bit'. 3) because my battery is full now I cannot do this heat-up trick. Thus, why not put my MacBook Air on the heater for a few minutes? And guess what !? I press the power-on several times: nothing, but then, after a few minutes: "boom!" (Steve Jobs style), its boots perfectly! And I have been using it for a few hours now.

My father suggested two possible causes:

A) two metal elements that should connect have been damaged and only just don't connect in normal state. When heated up these elements expand just enough to reach each other, allowing the MacBook Air to boot.

B) some dust is stuck between two elements that should not connect: when the atmosphere is very humid (as it is now where I am) this dust absorbs water, meaning it connects these two elements causing the MacBook Air to be unable to boot. When it is heated up, the water evaporates and it is able to boot again.

Either way, I would be really helped if someone can tell me what are the elements on the logic board involved in power-up, and how the paths run along the logic board connecting these elements. They shouldn't be many.

Thanx for that. I'll keep that in mind if light-heating doesn't work anymore 🙂

I've not made much progress since, but I did observe some metal pins on the logic board appearing more black than what might be healthy. Perhaps this is involved in the above problem.