CH340 Driver Installation Failure – Troubleshooting Guide

The CH340/CH341 USB driver is required to enable communication between your computer and devices such as the Ray5 MiniS laser engraver. Without the correct driver installed, the device may not be recognized by engraving software such as LightBurn or LaserGRBL, which can prevent normal operation.

This guide provides step-by-step troubleshooting instructions for installing and fixing the CH340/CH341 driver on both Windows and macOS systems.

I. Windows Systems

1. Common Causes & Solutions

（1） System Compatibility Issues

• Windows 10/11 usually includes built-in drivers, but auto-install may fail

✅ Solution:

• Manually download the latest driver from the official site: http://www.wch.cn
• Install file: CH341SER.EXE

（2）Old Driver Conflicts

• Previously installed drivers may block new installations

✅ Solution:

• Open Device Manager → View → Show Hidden Devices
• Expand Ports (COM & LPT)
• Uninstall all CH340/CH341 devices
• ✔ Check “Delete the driver software for this device”
• Reinstall the latest driver

（3）Driver Signature Issues (Win7 / Some Win10)

• Windows may block unsigned drivers

✅ Solution:

• Restart → Advanced Startup
• Select Disable Driver Signature Enforcement
• Install the driver again

（4）Insufficient Permissions

• Installation requires admin rights

✅ Solution:

• Right-click installer → Run as Administrator

（5）USB Cable / Port Issues

• Charging-only cables cannot transmit data

✅ Solution:

• Use a data-capable USB cable
• Prefer USB 2.0 ports
• Avoid hubs when possible

2. Confirm Successful Installation

• Plug in the device
• Open Device Manager → Ports (COM & LPT)

✔ Successful:

• USB-SERIAL CH340 (COM3) appears

❌ Failed:

• Yellow warning icon → reinstall or resolve conflicts

3. Alternative Solutions

• Try another computer to rule out system issues
• Use a USB-to-serial adapter (better compatibility):
  • FT232 USB-to-Serial Adapter
  • CP2102 USB-to-Serial Adapter

II. macOS Systems

1. Check if Driver Is Needed

macOS 10.13 and later versions may automatically recognize CH340.

Inspection method (terminal input):  ls /dev/tty.*

✔ If you see: /dev/tty.wchusbserialxxxx 

This indicates that the driver is working properly.

2. If Not Recognized → Install Driver

（1） Download Driver

• Official: https://www.wch.cn/downloads/CH341SER_MAC_ZIP.html
• Recommended (better compatibility): https://github.com/adrianmihalko/ch340g-ch34g-ch34x-mac-os-x-driver

（2）Allow System Extension

• macOS may block installation

✅ Solution:

• Go to System Settings → Security & Privacy → General
• Click Allow for WCH Electronics Co., Ltd.

（3）Restart the Computer

• Required to load the driver properly

3. macOS Troubleshooting

（1）Driver Installed but No Port

• Run: ls /dev/tty.*
• Replug device and check for new port

（2）Apple Silicon (M1/M2/M3 Macs)

• Official drivers may not be fully compatible

✅ Solution:

• Use the open-source GitHub driver (recommended)

（3）Permission Issues (Big Sur / Monterey / Ventura)

• macOS restricts third-party drivers

✅ Advanced Solution:

• Boot into Recovery Mode
• Temporarily disable System Integrity Protection (SIP)
• Install driver, then re-enable SIP

III. Alternative Solutions

If CH340 issues persist:

• Use a native-supported adapter: FTDI USB-to-Serial Adapter (best macOS compatibility)
• Or: Use Wi-Fi connection (if your controller supports it)

Important Notes：

• Always use a data USB cable, not charging-only one
• Restart your system after installing drivers
• Ensure only one software accesses the COM port at a time
• Keep drivers updated for stability

Conclusion

CH340 driver installation issues are usually caused by system compatibility problems, driver conflicts, permission restrictions, or hardware connection issues. By checking the driver installation, USB ports, cables, and system permissions step by step, most connection problems can be resolved quickly.

For better long-term stability, especially on macOS, it is recommended to use USB-to-serial adapters with native driver support when needed.