Visualize and interpret LED patterns to diagnose cable issues
I purchased a USB Cable tester to identify the pile of cables I have in my drawer. I selected a USB Cable Tester (affiliate link) on Amazon, out of many choices.
However it didn't come with a usable users manual, so I had to figure it out myself. (And I may be wrong!) I have tested this with all of the cables I have, but if you find more, please contribute on GitHub.
1. Plug in a USB cable into the receptacles on the left, right, and bottom of the tester. When the cable is attached, one or more LEDs will light.
2. Each pin has a specific function, and the LED will light up if that pin is connected in the cable.
3. A message will appear below the LEDs describing the cable being tested.
Note: The left side has two Type A receptacles; the top one is blue, and has the words "Type A 3.0", and the greenish one has the words "Type A 2.0": If your cable has a blue plug, you should insert it into the blue (upper) receptacle.
Note: Do not plug the ends of the cable into anything but the tester. Connecting it to a device or charger will damage the USB Tester.
Pinrow B
Pinrow A
This device tests USB cables, indicating which pins are connected and whether they are functional. It helps in identifying issues with USB connections and ensures proper functionality. Pinrow A and B refer to the two rows of pins in a USB connector, with each pin having a specific function.
Pinrow A will only have lights if a USB-C cable is attached. Otherwise Pinrow B lights will be used, for USB A and USB B plugs.
Each pin in the USB connector has a specific function, and understanding these functions is crucial for diagnosing cable issues.
Micro B and Mini B have `VBUS`, `GND`, `D+`, `D-` pins. They can also have an `ID` pin.
Type B 3.0 and Micro B 3.0 will have `VBUS`, `GND`, `D+`, `D-`, `TX1 +/-`, `RX1 +/-`, `TX2 +/-`, and `RX2 +/-` pins.
Apple Lightning connectors have a unique pin configuration, with `VBUS`, `GND`, `D+`, and `D-` pins. They also contain `ACC1` and `ACC2` pins (which have test pads on the back of the tester). They will often have the `Shield` pin.
USB-C cables will have both pinrows on each end ("top" and "bottom") and can contain all pins on this tester, except an `ID` pin.
Shielded cables will often have a `Shield` pin, which is used for grounding and reducing electromagnetic interference, and will light up the `Shield` LED.
The tester has two USB A ports, on the left side. One is green and the other blue.
Generally, blue indicates a USB 3.0 connection, while other colors indicate a USB 2.0 (or older) connection.
| Color | Location | Description | |
|---|---|---|---|
| White (required by USB standards) | Receptacles and plugs | Micro‑A, Mini‑A | |
| Black (required by USB standards) | Receptacles and plugs | Micro‑B, Mini‑B | |
| Grey (required by USB standards) | Receptacles | Micro‑AB, Mini‑AB | |
| Blue (Pantone 300 C) (recommended in USB standards) | Receptacles | Indicates a Standard‑A connector supports USB 5Gbps (introduced in USB 3.0), and possibly 10Gbps (introduced in USB 3.1) | |
| Teal blue (not part of USB standards) | Receptacles and plugs | Indicates a Standard‑A or Standard‑B connector supports USB SuperSpeed(+) 10Gbps (introduced in USB 3.1) | |
| Green (not part of USB standards) | Receptacles and plugs | Type‑A or Type‑B, Qualcomm [Quick Charge (QC)] | |
| Purple (not part of USB standards) | Plugs only | Type‑A or Type‑C, Huawei SuperCharge | |
|
|
Yellow or Red (not part of USB standards) | Receptacles only | High-current or sleep-and-charge |
| Orange (not part of USB standards) | Receptacles only | High-retention connector, mostly used on industrial hardware |