Insomniac Mac

I travel a lot for work. Many a nights I have been woken up in the middle of the night with my Macbook Pro going into this repetitive cycle where it wakes up, goes to sleep, wakes back up, over and over again. If you have a Mac you know that whir whir sound it makes when it wakes up. Think about sleeping in a hotel room, and having this happen over and over waking you up.

At one of our company meetings a few months back in Menlo, I had my Mac in front of me with the lid closed, and it kept waking up, making the whir whir sound, not only bothering me, but those sitting around me. The hypothesis was that I had flexed the notebook and the lid was not closing correctly. This led to a somewhat amusing episode of how many water bottles it would take to set on top of the mac, keeping the lid closed, to prevent it from waking up.

I have recently noticed that the issue does not happen while I am at home. Then on my last trip, the first night out it did not happen, and the second night it did. This really got me thinking about what was different about when I travel. The thing that came to mind is that at home I use my Broadband connect. On the road I use my Sprint WWAN.

This got me thinking about what I did differently between the two nights. The first night I disconnected my connection and then turned the card off. The second night I just turned off the card. After a couple of tests, the mystery of my insomniac mac has been solved. If I do not disconnect the air card before shutting it off, the mac gets into some funky state and continually wakes up.

I did a quick google search and nothing readily showed up as to why. Since I can solve the problem, by just turning the card off in the proper order, I consider the mystery solved for now!