In the HP Chrome book that I have, the microUSB port was partially loose. The port has two parts, one is the steel frame that is soldered to the motherboard at four points around the edges , and the second is the plastic insert that holds the five USB contacts that are soldered at the rear of the port to the motherboard. In my case, the insert broke off all five contacts and was actually sliding inside the frame.
My solution was to push the insert into its correct position (contacts aligned with solder points on motherboard), then with a wooden toothpick moisten with Super Glue, dab at all external spots where the insert touched the frame (don’t get any inside the microUSB connector!). Finally, using a conical pointed soldering tip, resolder the five contacts and check continuity. You cab add more Super Glue after all the contacts are verified to prevent future plug insertions from moving the insert and breaking the solder points again in the future.