yeah...
that usb ...forgot about that.
yeah if the usb is pooched...that will be a small task.
Are you certain that the microusb port is toaster strudel?
that is the big question.
you have tried to connect via different pc's ...
and / or different os's with it WHILE you had the monitor hooked up so you could see the results with your own eyes to verify that the micro usb port is smurfed ...right?
Otherwise triple check...quadruple check ...
if nothing is wrong ...for certain...then that is a tragic waste of labour and sweat to simply replace a possibly perfectly fine micro usb port.
Never take the word of the last owner as gospel.
For all we and you know... it is the operating system on device which started coughing up problems for the port. And troubleshooting with a good usb to micro usb cable and a few os's ...and possibly on device os re-installation may solve that...never know.
But if someone didn't take good care of the device ...then anything is possible.