A. Physical connection failure between computer and device
[ Phenomenon and Judgment ]
1. The connection/disconnection of the device appears cyclically.
2. The computer is always accompanied by a tone to plug in a USB device.
3. The computer keeps popping up the window of the device file manager.
4. The hardware device in the device manager interface keeps refreshing.
[ Solution ]
Replace the data cable, USB interface, and USB hub to eliminate the problem one by one. If there is a hub, connect the computer directly without connecting the hub; if there is still a problem, replace the data cable or change the USB interface.
B. Insufficient power supply to the USB interface
[ Phenomenon and Judgment ]
1. The device is randomly dropped, and can be maintained for a while after restarting the software.
2. After removing several devices from the hub, they will not be dropped. After plugging in, they will continue to appear randomly dropped.
3. Unplug the dropped device and plug it into the USB port on the back of the computer case. The device is no longer dropped.
4. The device is randomly dropped after connecting the notebook or all-in-one through the hub.
[ Solution ]
1. Replace the USB hub, it is recommended to use the SIPOLAR A-400 hub.
2. If you use other brands of hubs, you need to ensure that the hub has a separate power supply, and try to ensure that the hub's USB single port power supply 2A and above.
3. The number of USB ports of the hub should not exceed 20, try to use a 10-port hub to ensure stability.
4. If you use a notebook or an all-in-one, it is best not to connect more than 5 devices, control more devices, recommend using a desktop computer.
5. The hub should be connected to the USB interface on the back of the chassis to avoid using the USB interface on the front of the host.
C. Device Offline
[ Phenomenon and Judgment ]
1. After the device is connected,, discover the device offline through adb devices.
2. By clicking on the device diagnostics on the software, the diagnostic results show offline.
[ Solution ]
1. Connect the device to the USB port on the back of the computer case to avoid using the USB interface on the front.
2. Replace the USB hub or data cable.
3. Update the USB driver.
4. Reinstall the computer system, it is recommended to use Win10 and Win7.
D. Adb conflict with other helper software
[ Phenomenon and Judgment ]
1. The interface for installing and starting the service appears in a loop, and the button for connecting the device cannot be displayed.
2. Unplug one device and cause all devices to drop when connecting multiple devices.
[ Solution ]
1. Try to ensure that the computer environment is clean, do not install assistant software with adb.
2. Try to use the official driver of the device or use a third-party software such as Driver Wizard to install the driver, avoid using the mobile assistant to install the driver.
3. If the assistant software is installed, delete or set the adb of the conflicting software to not connect to the device automatically. If the problem cannot be solved, uninstall it.
E. device driver conflict caused it to drop
[ Phenomenon and Judgment ]
1. There is a conflict between different device drivers, causing all devices to drop.
2. When using a device alone, the connection is normal, and when another device is plugged in, the two devices cannot be used.
[ Solution ]
1. Avoid using two devices with conflicting drives at the same time
F. The device background is closed by the system
[ Phenomenon and Judgment ]
1. After troubleshooting hardware problems and connection problems, use the USB interface on the back of the chassis separately, the device still appears dropped.
[ Solution ]
1. Open the mobile terminal's self-starting permission, lock the mobile terminal background.
2. Device Settings - Battery - High Power Settings - Set the app to Unlimited.
G. Special settings for special devices cause to drop
[ Phenomenon and Judgment ]
1. The power saving mode or the Manage apps' battery usage of the Xiaomi device causes to drop.
2. Xiaomi device does not use official stable ROM, use unstable development version to cause to drop
3. Huawei device is not turned on 'Only the charging mode allows adb debugging' cause to drop.
4. ViVo X series, Y series device system kills the screening process and causes to drop.
5. The device system is rooted
6. The device system is equipped with a framework or software such as Xpose to modify the system settings.
[ Solution ]
1. Turn off the device's Manage apps'battery usage or power saving mode.
2. Avoid using an unstable system version, using the device's native factory ROM.
3. Huawei device settings allow adb debugging only in charging mode.
4. ViVo device back to the system version before June 2018.
5. Do not give the root permission when setting permissions after connection.
6. Avoid using third-party or other third-party frameworks or software to modify system settings.
H. device special features cause to drop
[ Phenomenon and Judgment ]
1. device split function causes to drop or cannot be connected.
[ Solution ]
1. Avoid using your device's split function when connecting to your device.
I. Third-party live or screencast software causes to drop or software crashes
[ Phenomenon and Judgment ]
1. Conflicts with other similar projection screen software
[ Solution ]
1. Avoid using other conflicting software.
2. Select the first one in the PC Acceleration of Device Settings.
J. USB connection is normal, WiFi connection causes to drop
[ Phenomenon and Judgment ]
1. When the USB cable is connected, the WiFi is connected normally. After the USB cable is unplugged, the WiFi is disconnected.
2. WiFi connection is unstable, delay or dropped.
[ Solution ]
1. Allow to run in the background, Set - Power and Performance - Apply Configuration, set the app to unlimited.
2. Ensure that the WiFi environment is relatively simple and avoid interference caused by complex WiFi environments.
3. The PC is connected to the network by wire. The device is connected through 5G WiFi. The distance between the device and the AP should not be too far. The number of connected devices in the same AP should not be too much.