Chosen Solution

I charged my Air overnight and when I tried to turn it on in the morning it didn’t boot. I tried plugging in the Magsafe in to find that no light came on. Doing an SMC reset didn’t work. Later on, I had the MagSafe plugged in for over an hour and the orange light came on, and pressing the power button turned it on, albeit it, was very slow. If I unplug the Magsafe cord, after 5 seconds it abruptly turns off. I doubt it would be any water damage, since I haven’t spilled anything on it, nor was I in a humid environment. Potentially the battery might have something to do with it; the “Service Battery” notification came up the day before, although it seems to charge just fine, and as I type this, says the condition is “Good”. My research says that it could be a bad Magsafe connection. Any help would be awesome. EDIT: Screenshot attached of CoconutBattery, doesn’t seem to be a battery issue, although 711 cycles does seem a bit extreme. I’ve also noticed that the MacSafe brick and the Mac itself is scalding hot, if that is any help in assisting. The male and female MagSafe connectors are free from debris, the MagSafe connector is about two months old, the other one broke after 4 years.

Well, the battery is charging and while not young still has some life left. With almost full charge are you encountering the same issue that the system shuts down when you disconnect the charger? If you do that’s telling me the switching logic (MOSFET’s) on the logic board that are damaged. a common cause to this is using knockoff charger which looks like an Apple MagSafe but just isn’t! Please don’t buy a cheap knock off unit as they will damage your system! Get the REAL Apple unit directly from Apple. This is what your system needs: Apple 45W MagSafe 2 Power Adapter for MacBook Air ● Don’t Replace Your MacBook Charger With a Cheap Knockoff ● OEM MagSafe Chargers vs Cheap Imposters: Teardown for Truth ● Lacking safety features, cheap MacBook chargers create big sparks ● FAKE Magsafe MacBook Chargers on eBay - Watch before buying a Mac Charger

Check the magnetic male and female ie charger and laptop for minute ferrous particles - they could be causing problems. Have a good look at each with a magnifying glass - in any case blow out contacts with compressed air. Or pick out with plastic tweezers or something non conductive.