RE diddi's advice , I guess it may be worth trying to do the repair job - I'm glad someone knows a little about it (I'm not sure my first attempt at soldering would result in a fix or a disaster though, if I were in these shoes). I read some similar description for fixing usb's online but since I've never done anything close I had no idea if it was in the realm of possibility or not.
I've never had a USB fail me - only recently I discarded some 4-5 year old devices as getting too old to be sure about. There's a life expectancy based on number of read/writes but how do you measure that in real life (?). Edit: oops -- I take this back. I did have one that literally fell apart on me, but had no important data on it.
The rule about files is that a file that isn't backed up doesn't exist. For any important work you do you need to decide what's the worst case you are willing to live with (losing a days work, a weeks work, an afternoon's work), and backup accordingly. At work you'll have IT support for this, but at home you have to do your own backups - a thumb drive is as a rule unsafe since they can be lost, so I'd consider such devices as requiring backups after every work session (i.e., to the laptops' drive before you log off). Live and learn.