Chosen Solution
MacBook battery emptied out as I forgot to charge it. As predicted, it shutdown. So when I click on the battery indicator button, it is flashing green very quickly on the first dot. however, when I plugged in my MagSafe cable, its indicator stays on green rather than changing to orange. But when I unplug it, the MacBooks battery indicator starts flashing again on it’s own. So I’m not sure if it’s charging or not. My Mac isnt turning on, although I just plugged in the charger 15 minutes ago from the time of this post. Should I wait longer or is something wrong?
First step here is to disconnect battery as your Mac doesn’t really need it for normal operations but a faulty battery may prevent system start if internally shorted and in some quite rare cases it may even damage the logic board. Plug back magsafe and see if the Mac starts on its own as it should. If it does you would want to try a battery replacement, otherwise a board failure may be the issue to take care of.
Given the systems age I’m sure the battery was on its last legs. A flashing battery checker LED is the bad battery warning (just like the menu icon). You’ll need another battery to checkout your system MacBook Pro 15" Unibody (Early 2011-Mid 2012) Battery and here’s the guide to do it MacBook Pro 15" Unibody Mid 2012 Battery Replacement You may also have a logic board issue! If your MagSafe chargers LED never goes to Amber that’s a sign the charging logic has a problem. This often happens when a knockoff charger was used instead of a real Apple unit OEM MagSafe Chargers vs Cheap Imposters: Teardown for Truth
