What is it?

This is a USB type A to type B version of my popular USB micro cable tester, using the original large-size type B connector (that doesn't seem to have more specific name other than "USB").

It works the same – plug a cable into both ends of the tester to test continuity of each pin.

Additionally, test pads are broken out if you want to test any of the cable's lines for resistance or inductance using a multimeter. This can be used to infer the gauge of the wire.

Note

In the currently shipping version there is a mistake in the silkscreen, wherein the cable is still called a "mini" cable.

Usage instructions

Take both ends of the same USB cable under test and plug each corresponding end into the USB type A and type B ports. Do not leave the cable connected to another device while it is connected to the tester.

If the data lines work, the included battery will light up the corresponding LEDs in the "data" section. This means the cable should be able to transfer data and to charge a device with higher power, since these lines are needed to negotiate higher power draw than the default 500ma according to the USB spec.

You can also tell if the USB cable is defective or worn out internally if one of the LEDs don't light up or if any of the LEDs flicker or switch erratically when the cable is handled. If this happens the cable under test is probably not suitable for use and should be discarded.

For more advanced users, test pads are exposed so you can easily measure the resistance, inductance or other properties of a USB cable using a multimeter. You'll presumably want to remove the battery from the tester while doing that.