Won't boot unless I remove the battery.

Hey guys,

I've got a customers MacBook Air, 13" Mid 2012. It was brought to me with the symptoms of it won't boot.

I have successfully got the machine to boot, but only after I remove the battery and let it sit for a minute.

I've tried:

- Resetting SMC

- Upgrading SMC (it was outdated)

- Different MagSafe adapter

- Booting without the battery (it gets very slow when the battery is disconnected)

- Booting without the MagSafe (won't boot at all, but it will stay running after a successful boot)

This is reproducible, after shutting down the machine it won't boot without first removing the battery. It will restart properly however.

Anybody have any ideas?

Thanks,

Eric