Got a used 2005 G4 Mini 1.42GHz with a very strange problem. Wonder if anyone else has seen this Basically, one screw that secure the optical disc drive to the interposer board would cause the HDD to disappear (no HDD found during boot) if the screw was fully tightened. If the screw was backed out 2 turns, HDD is discovered. Here is a pic of the interposer board. The screw in question is through the hole ZT1 on top left corner of this pic. Someone has messed with the optical disc drive before I got this mini. Perhaps they might have damaged the interposer by over tightening or had the screw installed at an angle.