Originally Posted by
Prof_Dr_G
I should also not that I often fly Singapore Airlines - EWR/SIN and LAX/SIN, and I never have the problem. The same is true with ANA when flying IAD/NRT. I have a converter for UA, and I have had no problems there, but I try to avoid them whenever possible because they are so disrespectful. It is only with Delta that I have had problems.
The problem is in power spike (more above 100W) at the moment of connection the adapter to the socket outlet wich shut off the in-seat power. It's a known problem with some HP, Dell, and Lenovo laptop AC power adapters. New planes (SQ, many others) manage it somehow, but not the old 747.
Therefore it actually doesn't matter what is real power consumption of your laptop - it's the adaptor issue.
You can check your adapter even without laptop by connecting to any low-power (like 80 or 100W) in-car AC adapter. I believe that in-car adapter will just shut down after connection.
The best solution is to change the adapter (may be less powerful as
kerbo suggested, or even OEM). Another, but more complicated way, is to modify the adapter (force it to make kind of slow start).