I replaced the PS in an eMachine T1860, and it came up fine .... so I continued with Windows updates etc, rebooting a number of times without issue. However, when I rebooted after installing SP2, the video never returned. I now get absolutely no video when booting, including the bios screen. It powers up, and spins the hdd, but that's it. I've tried a separate known working video card .... nada.
Ya just gotta love these eMachines!