Good thing there are these parts

The following case from his own experience:
To connect external 3.5 "hard drives via USB 2 I had cable" plug-A to plug-A "already covered and this worked well.
When I wanted to reorder these, these were sold out indefinitely, and all substitute erwobenen other versions did not run reliably.
So I compared metrologically ever a cable that was safe and one that was unreliable.
It turned out that the reliable cable had a contact resistance of 0.1-0.2 ohms, and the other - cheap crimped versions - up to 1 ohm. Although this seems little, that is to say, however, that when turned on an external hard drive on the laptop that wants to pull from there via USB to 1 A, a voltage drop of 1 V (R = V / I ==> U = RxI)
is produced at the plug connection, so the hard drive of the 5 V only 4 volts abbekommt (!), and no longer runs reliably.

The solution was now: buy plug and solder itself. A measurement of the finished built cable then gave the same data as the cables are no longer available.

And: The harddisk worked right away!

The only point that makes some problems, is the guard that goes difficult on the metal casing. Solution: Make assembled connector vertically and gently pack with the longest possible telephone pliers disconnect the plug approach or the plug neck top and come with a small hammer or karate techniques wisely the Platikhülle down.