Originally Posted by
jmastron
Not tried on Delta, but I've had bad luck getting power outlets to work on various United planes; often it seemed like the issue was a loose/intermittent connection to the plug, with the outlet cutting off after a bit. Following a suggestion from FT, I tried using one of the European 2-pin adapters on my laptop's plug, and had much better luck. The round pins are longer and thicker and seem to make better contact. Worth a try...
This. The two-prong 'japan' style plugs (that are both the same size) don't work well. They aren't deep enough to reach the terminals (or something). These are often used in two-prong laptops or cell phone chargers.
I use a UK adapter and plug my phone charger into that. Works great. Phone charger alone? Doesn't work at all.