Weird, Annoying, (hair-tearing), Problem

When I try to connect my e280 to the computer it says that its connected for a second then it immediately disconnects.  It connects again but it disconnects immediately again. This continues to happen until I unplug my device and I am unable to add or remove anything.  I have reformatted it and reset it to the factory conditions.  In the settings menu I never had A setting “USB Mode” b/c I have been seeing that as an answer for alot of these problems but It wont work for me. Please help me this has been going on for about a year and it is driving me CRAZY.