Have experienced continuous problems trying to get laptop power from NW WBC seats and also economy seats on NW A330. Get power for maybe 10 seconds, then power dies -- pull out plug -- green light shows again -- plug in -- 10 seconds green light, then dies -- was once successful for 30 minutes on an HNL-NRT segment a year ago, but that failed too after 30 minutes. My laptop runs on 220V/110V dual current brick powersupply, but normal use is 220V in Korea, so I wonder if it is trying to pull too much power? I have tried removing the battery from the laptop as some airlines advise, but does not help. Any suggestions?