My dell mini has been bricked, following drop from about 1ft. It was on at the time.
The trick with fn+end works, as far as powering usb ports (there is a spike of power on usb ports whenever both LEDs flash - tried that with oscilloscope).
I checked big chips and soldering on them as much as I can (I don't have an x-ray machine, which is the way you do this at factory, when there's a busted batch of boards).
Homegrown method is to apply a bit of pressure to each chip and trying to boot it up.
It basically comes up, spins up a disk, and shuts itself off pretty quickly. I did remove all extra boards, tried different memory, with/without display, with/without keyboard, with/without memory too. No good.
But powering up with fn+end flashes the LED. So there's hope the thing isn't completely dead, but for instance the BIOS flash got somehow corrupted when there was a very short short-circuit somewhere on the board when it was dropped.
So fishing ideas here. Plus upgrading BIOS regularly is quite recommended, at least for some serious desktop/laptop computers. Wouldn't count DELL in that category tho