Some non SGI stuff....
Bought this Thomson DHD4000 Freeview PVR, it's great apart from the noise of the HDD and the Fan which are unbearable. Have a look inside:

Note disconnected HDD Power Supply.
Unplugged the drive and took the caddy out, gave myself heart failure when I plugged it back in, got a flashing, then constant orange light, where it should be green or red, on the front. I'd got the ribbon cable for the HDD the wrong way round - it's completely symmetrical.