When your PC flags a Jieli device as an "Unknown Device" or shows a yellow exclamation mark in Device Manager, you can resolve it using three primary methods. Method 1: Use Windows Update (Recommended)
If your computer has a "Jieli Technology USB PHY 2.0" device showing a yellow exclamation mark in Device Manager, here is the correct troubleshooting method:
Look closely at the > Optional updates section. Hardware drivers for generic chipsets like Jieli are frequently categorized here. If you see a driver listed under "Jieli," "Zhuhai Jieli," or "Generic Bluetooth," check the box and install it. Method 2: Use Windows Generic Bluetooth Drivers Jieli Ac4100 Bluetooth Driver
Right-click the problematic device and select . Choose Search automatically for drivers .
If the driver is installed but the device still does not work, try the following solutions: When your PC flags a Jieli device as
Standard Bluetooth drivers built directly into Microsoft Windows or macOS.
Click . Click Have Disk... and then click Browse . If you see a driver listed under "Jieli,"
Often found in car Bluetooth-to-USB adapters, wireless headsets, and generic USB Bluetooth 4.0/5.0 receivers.
Connect your Jieli AC4100 Bluetooth device or USB dongle to your computer. Right-click the and select Device Manager .