Originally Posted by
mersk862
It's been very inconsistent for me on 737-800s; on some planes it works fine, others it doesn't work at all, others I need to constantly fidget with it to keep power supply going.
Given that it works on about half the flights, I figure it's not a problem with my laptop, but more of a problem with the source itself - I tend to just mention it to the crew, asking them to put it in the log for when maintenance can take a look at it downline when there's a chance.
Your power supply is probably drawing more power than the port is supposed to be able to provide. Whether it works or not is probably a function of a number of things, including whether your batter is charging (this increases the load substantially), and other variations in the plane. Try unplugging your battery and seeing if it works.