Device only turns on when plugged in, battery won't charge

[smlksmth]

I have searched far and wide to try and solve this issue but have had 0 luck.

I have an early 2015 Macbook Air (A1466) that I've kept in great condition over the years. It's never really left my room/desk and I've gone far out of my way to keep it in this condition because of how much I like this computer.

So, it had been a few months since I last used it (new job, work computer, travel all the time) and I realized the charger had been disconnected at some point meaning the battery had been likely sitting there completely dead for days, weeks, possibly months which I understand is not great for a Lithium-Ion battery?

I just tried to power it on for the first time the other day and it boots up, while plugged in, and loads seemingly normal but when the computer is finally completely started up the battery is indicated as "not charging" when clicking on the icon from the taskbar and the percentage is stuck at 1%.

The orange light on the MagSafe charger is on when plugged in.

The steps I've taken so far.
-Reset SMC a few times
-Reset PRAM a few times
-Option clicked on the battery to see a report and it shows as "normal"
-Downloaded coconut battery and that also shows as "normal"
-Checked the cycle count which is currently sitting at about ~310 which seems well under the expected failure point
-Removed my battery and checked the inside of my computer for corrosion or any other type of damage, found nothing
-Inspected the battery for any oddities or swelling, found nothing.
-Tried multiple MagSafe chargers
-Charged another Macbook using my MagSafe charger

A friend of mine had me take some photos of the IO board to see if he could figure it out and isn't sure but seems to think there might be something up with that? I've attached those photos here but soldering and electrical work is far beyond my skillset.

I understand I might have a broken component somewhere but I just want to find out so I can avoid paying Apple $500, which they quoted me before even understanding the issue themselves.

 

[kohlson]

I think the most likely cause is a dead battery. Question - when the computer was used regularly, was it often/always connected to power? If so, the battery almost certainly needs replacement. I've had to replace an MBA battery with less than 300 cycles, was about 3.5 years old, and was nearly always connected to power. Batteries don't like constant power connection.

 

[smlksmth]

I think the most likely cause is a dead battery. Question - when the computer was used regularly, was it often/always connected to power? If so, the battery almost certainly needs replacement. I've had to replace an MBA battery with less than 300 cycles, was about 3.5 years old, and was nearly always connected to power. Batteries don't like constant power connection.

It was connected fairly often but I was pretty good about disconnecting once it was at 100% especially if I was done using it for the day.

 

[smlksmth]

I think the most likely cause is a dead battery. Question - when the computer was used regularly, was it often/always connected to power? If so, the battery almost certainly needs replacement. I've had to replace an MBA battery with less than 300 cycles, was about 3.5 years old, and was nearly always connected to power. Batteries don't like constant power connection.

Yes, it was often connected to power but I was pretty good about making sure it wasn't left on charge too much once it was back to 100%.