Mini USB - B cables issues

[trastikata]

I've just found out why my USB built devices always work at my computers and sometimes don't work when given to other people ... and this happens only to the devices with Mini USB port, not the Micro USB nor the Standard USB port.



well they work, but seems the cables they are using are not always good.

there are 5 pins in the Mini USB connector and pin 4 is the ID pin, which must be tied to ground for the PC to properly recognize the USB device.



looks like some Mini USB B cables, not the Micro or standard USB, have the 4th pin missing:



when they should have all 5 pins:



or the 4th pin should be tied to ground (5th pin) internally, like here:



And here's what ChatGPT says ...

I have a USB device with Mini USB plug. The USB jack has 5 pins. I see some Mini USB cables have 4 pins in the connector and they don't work, but some cables have 5 pins and they work, why?

Why some cables don't work:

    4-pin Mini USB cables: These omit the ID pin (Pin 4) entirely, or leave it unconnected. These are typically charging-only or basic data cables for devices that don't need the ID pin.

    5-pin Mini USB cables: These include the ID pin, which may be:

        Floating, used for standard USB device operation

        Grounded, used to signal USB OTG (On-The-Go) host mode

        Connected in a specific way for device-specific functions

Why this matters:

Some USB devices require the ID pin to be present or connected a certain way to enable full functionality, like:

    Switching between host and peripheral modes

    Enabling specific features like firmware updates

    Detecting cable type (especially in proprietary setups)

4-years long mystery solved. And makes me thinking - how much would the manufacturer save by removing the 4th pin? And if decided to save few cents over million cables, why not simply tying the 4th pin to ground at the PC jack, which would make the cable fully functional while keeping the cost saving? Or hey simply want us to keep buying cables until we get a 5-pin Mini USB cable?