What happened here was a complete surprise for me. I always treated the connector with great care, never pulled the USB cable, never pushed it too hard. Turns out, that my mishap was caused by a very unfortunate coincidence of poor design of the USB 3.0 Micro-B connector and less-than-perfect mechanical performance of ROHS solder joints.
The plastic part that you see sticking from the back of the connector is the plastic insert with contacts. As you can see it in the pictures below, only one of the leads shows signs of mechanical stress. The rest of the pins were either not deformed at all, or bent very slightly.
The picture below shows Amphenol's USB3.0 connector similar to the one mounted on bladeRF. The plastic insert is held in place by the two indents in the metal frame (circled in red), which recess into cavities molded in the plastic part. Assuming sufficient mechanical strength of the insert's material and tight mechanical tolerances, this mechanism should be sufficient to firmly bind the two parts together and prevent them from moving. The load caused by plugging and unplugging the cable is transferred on the metal frame, which is firmly attached to the PCB. The stress caused by residual movements of the insert due to slack is dissipated in the vertical section of the pin, and the load exerted on the solder joints under the pins is minimal.
|The marked indents in the metal frame are supposed to hold the parts of the connector together.|
|Damage to the plastic insert.|
Update: Second part of the story describes my first, partially successful attempt to replace the connector.