Everything is made like this (ps3 has ylod,360 has rrod etc.), but maybe they are not actually made like this, it is because we "push" them that destroy them... You see, for example the "old" ps1 was not that fast as the ps3, so the electonic parts inside the ps1 will last longer compared with the one of the ps3(even if ps3 has some newer and better materials) and the reason is that the ps1 will not get "pushed" to work faster and faster as the ps3... Now about your n900, I don't know why it acts like this... It is just strange because it was actually working and it was just left in the box without really work... P.S: Do you have the n900 with the broken usb as well?? If yes, why don't you try to repair that one?