Temperature Dependence of Mac Air (Mid 2012) On Startup
I bought this Mid 2012 Mac Air about that same time, and it has been a wonderful computer. A total trooper. I have replaced: the keyboard, battery, Airport card, power outlet/charger, and now even the motherboard. Most of it was my fault: I’ve spilled liquids on it at least 3 separate times, and for the most part, it has still delivered exceptional service, in spite of the reckless treatment.
So now, I swapped my i7 2.0 GHz / 8 GB Mobo for the i5 / 1.8 GHz / 4GB Mobo, after my latest spill. I got the used 1.8 GHz board off of Ebay for $150, which I would consider a good deal. It worked out of the box, without really any perceptible impact on performance for day-to-day activities. However, I noticed that on occassion the new motherboard would have fits where it would not start up. It would take 5-20 cmd+ctrl+power hard resets in order for it to boot correctly. The problem seems to have evolved, so now that if the laptop is at all warm, then the computer cannot restart. I recently updated the OS to High Sierra 10.13.6 and it wouldn’t boot up for days. I thought it was lost. Surprisingly, though, I had this theory that the computer seemed to boot better when it was cold. So I put the laptop in the fridge for an hour, pulled it out, and it started up as if nothing ever happened. I have repeated this episode maybe 10+ times now, so I am certain that the issue is reproducible. The funny thing is that, once it is booted up, the computer works totally fine! But due to its temperamental state, the computer cannot be used mobile, and has been relegated to use as a desktop only.
So the fact that the computer won’t start if it is warm (temperature-wise), suggests there is some component on the board that is physically damaged, or on some borderline of tolerances. I have no idea if it is possible to troubleshoot this. I haven’t looked to see if I can observe visually any damage on the board. But, since it just fails to boot, but the computer itself works fine afterward (even when warm), I was wondering if there was a way to manipulate the hardware, perhaps disable some checks to prevent it from failing to startup?
I know this is a longshot, but I would love to hear what you think about my issue. The alternative is to just buy another 1.8GHz/4GB mobo and be done with it. But I wanted to see if I had other options first.