I'm one of those guys that runs a powerful laptop for engineering work. I can attest that I've never gotten it to work on any 737 no matter how it is plugged in or from one seat to another.

I run the factory supplied 135W adapter (Thinkpad W510), it never works, it'll trip it every time on a 737. On a 777, it works just fine. And no I can't use a smaller power supply, if I use a lower wattage adapter, BIOS will slow the machine down to being just plain unusable. Its no fun carrying around a 2lb brick...

So I always go on with a full battery, low brightness and I'll get about 90 minutes before I have to go to watching the History channel........

As a point of reference, with a previous machine that only pulled 90W, it was hit and miss on 737s, usually hit (Thinkpad W500).