How digital companion turned into a mobile hard drive

I have a digital partner, but basically when the use of mobile hard disk, but in the use of the time, do not know if power is not good or bad contact, and sometimes plug in the interface, non-recognition; is sometimes hard to find when broken, There is, according to the time switch, but the old auto-off, a red indicator light often, when I used the power play, I do not know how such thing!
now to see friends have said that the boxes will be able to change mobile hard disk when using a mobile hard disk, do not have to plug the power supply is not really ah! The home itself how it turned it? In addition, the companion digital data lines than mobile hard disk data fine line, this is also related to ah? Line data is not universal ah? Can I change the dual-interface data Line?
Are really suffering, I would like to buy a mobile hard disk! But this also reluctant to help find a solution how to solve ah?

How it has been, ah well.Multi-purpose!