My USB hub has 4 ports for device connection, and one extended cable than can go into power. None of the 4 ports are connected with any device now. 

If I connect the extended cable with PC (which cable is only meant to go into power) , the hub lights up and is recognized by the *Windows 7 Device Manager*.
My mouse and keyboard would work just fine with the hub. 

Alternatively I could also use one of those USB male-to-male wires to connect one of those 4 hub ports directly with my PC. Then the hub would light up, but would not be recognized (not even a message indicating that). No mouse or keyboard could be used with the hub either. The mouse would light up, the keyboard's *NumLock Led* would not. Even I have made that extended cable go into power, but it's no use.

How to explain that? This would be one of a series of questions since I am debugging a home network. Hope that this would not be considered a silly question, I do not have a decent knowledge about *Hub Mechanics*. 

[The USB hub](https://i.stack.imgur.com/jzI26.jpg)