The driver provides several functional enhancements beyond basic hardware switching:
Because "FJ-U02S" is a generic OEM label, there is rarely a single "official" manufacturer website. However, you can source a working driver using one of the three methods below. fj-u02s driver
| Error Code | Message | Solution | | :--- | :--- | :--- | | | This device cannot start. | You likely have a counterfeit chip. Uninstall the current driver and install Prolific v3.3.2.105 (legacy). | | Code 28 | Drivers not installed. | The Hardware ID is unrecognized. Use Method 1 (VID/PID search) to find the correct chipset driver. | | Code 31 | Device not working properly. | Another application is holding the COM port. Restart your PC or use Mode comX: baud=9600 in CMD to reset it. | | No Yellow Bang, but no data | Device appears fine. | Check your baud rate mismatch (e.g., device expects 9600, terminal set to 115200). Also, verify null modem cable pinout. | | You likely have a counterfeit chip