I've recently been fighting a bad connector for my snow plow. The parts place didn't have one in stock, nor did their supplier. In the end I was looking at like fifty bucks and a month or two wait. Bag that! I decided to rebuild the connector myself.
But I want to mention that I've used this exact same technique many times in the past to rebuild USB ends and also headphone connectors.
So often in this age we throw away and buy new stuff when all that's wrong with it is a faulty connector that could have been fixed in less time than it took to get to the store and back anyway! Wasteful, expensive, and CRAZY!
Enough rant. Here's how it's done...
Step 1: STOP! Try the Easy Way First!
I wouldn't go that far, but it would be pretty dumb to rip the thing apart if all it was was a little dirty.
Just spray a generous amount in there, let it dry, and give it a try.
Step 2: Get Into It
On connectors like this one you can start at the pin end and/or the wire you're targeting and cut along, following its path through the plastic jacket.
Cut all the way down to the wire, but try to minimize cutting into the wire itsself. It sometimes also helps to wedge the plastic open as you go so you can see inside easier.
USB is a litte different here. All the wires are inside a crimped metal can inside the plastic jacket. Just cut one entire half of the jacket down to the can and pull the whole jacket off. Then you can pry with a small screwdriver to pop the can apart.
Step 3: Make Some Connections
1) The connection between the wire and the connector pin has come loose.
2) The wire itsself has broken (almost always at the base of the connector).
If #1, just clean up the wire and the connector and solder them back together.
If #2 you'll need to remove all the connections, pull in more wire until you're past the damaged section. Cut, strip, and solder.
The second situation is much more common, especially with plugs for your personal electonic devices that get a lot bending and flexing on a daily basis. This time I had an even easier job and just had to clean the wire and solder the pin back on.
Step 4: Put It All Back Together
From there, seal it up all nice with electrical tape or liquid plastic.