2014 Macbook Pro power button only works after battery gets reconnected

[linkmaster6]

I've gotten my hands on a 2014 Mac Book Air (i5) that was sitting around unused for the past 3 months or so.
When plugged in the charger light will go from green to orange. If go to turn it on, the charger will turn green for about 2-3 seconds and then turn back no orange. But the unit will not power up.
Tried doing the SMC reset, still acts the same as above.
If I disconnect and reconnect the battery and connect the charger it will turn on fine. When first booted it showed the battery at 75%, I allowed it to charge to 100. After getting a full charge I disconnected the charger and left it to play youtube videos for a few hours, no problem running on battery power.
Decided to turn the unit off and tried to power it up again, but same as before, no power no boot, charger light acts like it did before.
Disconnecting and reconnecting the battery gets it to boot each time.

Any idea if this is a logic board or battery problem?

 

[chscag]

It could be a logic board problem. It could also be a failing DC input board which connects to the logic board and provides the circuitry for charging. It appears the battery is okay on the MBA since you're able to run for several hours playing videos.

The DC input board is not expensive if you decide to swap it out. You may be able to find one on eBay or perhaps from iFixit: The Free Repair Manual.

 

[linkmaster6]

Sorry to be MIA, I'd gotten a replacement DC board and tried it out but still get the same results. Mac will still only power on when its given a chance to be completely disconnected from power, so if I have the battery disconnected and disconnect/reconnect the power adapter for a few seconds it fires right up. But if I have the battery disconnected, connect the AC adapter, start it up/ shut it down, it will not power up afterwards unless the adapter gets disconnected.
So outside of it being the logic board, I'm a bit stumped

 

[chscag]

But if I have the battery disconnected, connect the AC adapter, start it up/ shut it down, it will not power up afterwards unless the adapter gets disconnected.
So outside of it being the logic board, I'm a bit stumped

Yeah, it's a tough choice to make - whether to continue trying to repair it or live with it. The DC input board was the least expensive way, but if it's a logic board problem, it may not be worthwhile to repair.

 

[jasongoldworthy]

just a question here


has it gotten wet ?

as it could be there is some corrosion on the logic board,

 

[linkmaster6]

It was definitely a worthy gamble on the DC board, but I'll have to live with using it with the battery disconnected for now

 

[linkmaster6]

Wet in the sense of direct water on the keyboard or through the side? Not that I can see, I'm going to remove the logic board tomorrow and check the other side as there doesn't appear to be any sign of corrosion on the bottom side of the logic board (No obvious signs, no water stains) But it very well may have been stored in a cold damp area before I got it.

 

[linkmaster6]

Got a look at the backside of the logicboard, definitely got moisture on it. Found a small crusty green spot and the exposed copper solder points are all showing signs of corrosion. So mystery solved. Thanks for the help guys

 

[jasongoldworthy]

yeah defo water damage then

try cleaning up the area with isopropyl alcohol it may solve the issue

or upload an image of the damage so we can take a look ?