USB 2.0 Cables and Connectors Class Document - Measurements and inspection tips

[Kiriakos GR]

I did started inspecting USB cable assemblies, by checking actual wire quality and measuring voltage drop, with out reading first USB Cables and Connectors Class Document
https://www.usb.org/document-library/cables-and-connectors-class-20

Any one having experiences at using high-end test and measurement equipment, he will discover that they are references within this document, which they define, best testing setup for its one electrical parameter testing.

Connectors accepted contact resistance, and how to measure it.
Aloud voltage droop at 5V (lowest limit)
Use of LCR meter for capacitance inspection at 1kHz

Additionally I feel today more knowledge rich, because at the reference about mechanical tests, Mating/Un-mating, I did not have any awareness of actual specifications.

At my very own first tests, I did succeed learning by the hard way, that USB female connector Mating/Un-mating force, this is critical detail, for having lesser possible electrical contact resistance.
If you are up to get involved with precise measurements of USB 2.0 cables power delivery, the first priority this is having a test setup with undamaged USB connectors.

I did come and in to a second realization, that USB connectors over old PC systems, these they might be today out of operational life cycle, and these old female connectors they require repair by installing a new connector.

As example this might be old DELL workstation,  with two USB 2.0 ports at the front, because of easy access the user will plug anything and everything to them, by leaving unused USB 2.0 ports at the back (motherboard side).

An second example this might be industrial PC, regular PC case with USB 2.0 ports at the front.
These connectors might appear as functional when connecting Low-power accessories (keyboard or mouse), but when the loading goes at 500mA, an damaged connector will not deliver this current with out a huge voltage drop.

Un-mating Force test procedure
USB.ORG documentation this mention test by the force of 10 Newtons.
This can be easily translated to metric, by the use of 1Kg of weight instead.
Such force can be simulated by using old style kitchen spring scale (with a hook).   

mating Force test procedure
This test procedure require 35 Newtons as maximum.
This is equal to 3.56 Kg

Today I know that when I plug a USB connector and this goes-in effortless, this part it is now mechanically damaged.

My current thoughts, we servicing all sort of things, we never paid too much attention at predictive maintenance and inspection of USB 2.0 ports and cables, which still is a critical component, for data communication and power delivery.

The content of this article this will grow more, I am planning to add photographs and details, of my own properly made verification tests. 

[Kiriakos GR]

There is also and a second link https://usb.org/sites/default/files/202506%20PD%20Delivery%20Package_0.zip

This is a huge pack of additional educational material.
I am also going to give it a good read.

Knowing well your enemy, this is best advice to follow, before you start a battle with him. 

[Andrew-88]

You did succeed to motivate me enough, so and I to have a look of this documentation.