I finally got a used Mercury laptop for cheap. It had a bad logic board. I can confirm that the logic boards and keyboards on the Onyx and Mercury are not interchangeable. The Onyx uses PC 133 RAM so it can be used in a Mercury (PC100) but not vice versa. However, I was able to successfully transplant the Mercury's LCD assembly into the Onyx and now I have video. The optical drives, modems and hard disks are also interchangeable.