I have been repairing a water-damaged MacBook Air 2015. Initially the machine would only boot with the battery disconnected and power connected, but then die after around 20 minutes. The MagSafe light did not light up at all but still provided power to the computer.

I replaced the battery, which made no difference. I replaced the logic board which then allowed me to boot with the battery & power connected. The MagSafe still did not light up and the the computer would die after around 20 minutes.

I have just now replaced the I/O board. The MagSafe still does not light up and the battery does not charge, but the computer runs as normal with all apps open and full backlight etc.

I have reset the SMC and PRAM to no effect but I can't think what I could possibly replace at this point. The only remaining original part is the ribbon connector that links the I/O and Logic board but that looks in good condition. Does anyone have any suggestions at this point?

System report says that there is 0 mAh charge remaining in the battery

Battery: Yes

Charging: No

It also says that cycle count is 729 which it definitely isn't as it's a new battery.

Any help appreciated.

  • There's nothing strange about those issues given a liquid damaged computer. There is a failure on the logic board circuitry that connects it to the battery. That logic board needs to be repaired or replaced.
    – Allan
    Feb 14, 2019 at 19:48
  • @Allan The question mentions that the logic board was replaced.
    – dwightk
    Feb 14, 2019 at 20:07
  • He replaced it with a faulty board. It's safe to assume this was a purchase in the secondary market like eBay or Amazon. The logic board is 4 years old now and is not likely to be be sourced from Apple for $700+ when a brand new units start at $1000
    – Allan
    Feb 14, 2019 at 20:12
  • Allan - You are right that I replaced it with a 2nd hand board. I do find it odd that the new board would be flawless, except for the exact same issue I was having in the first place though. I will contact the seller of the board, although I'm not convinced that a brand new board would fix the issue.
    – JBos
    Feb 14, 2019 at 20:58
  • Water damage is a very common affliction and not charging/powering up is a very common symptom probably because it's the circuit with highest current going through it. I've bought second hand replacement boards before and have returned a majority of them because they were as damaged or worse than what I was trying to fix. The best solution was having the actual board repaired.
    – Allan
    Feb 14, 2019 at 21:16


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