1# Fixing Image Burning Errors 2 3 4## "Error: Opening COMxx: Access denied" is displayed when I start image burning 5 6- **Symptom** 7 8 "Error: Opening COMxx: Access denied" is displayed after a serial port is selected to start image burning. 9 10 **Figure 1** Failed to open the serial port 11 12 ![hi3516-faq-serial-access-denied](figures/hi3516-faq-serial-access-denied.png) 13 14- **Possible Causes** 15 16 The serial port is in use. 17 18- **Solution** 19 201. Search for the terminal using serial-xx from the drop-down list in the **TERMINAL** panel. 21 22 **Figure 2** Checking whether the serial port is in use 23 24 ![hi3516-faq-serial-check](figures/hi3516-faq-serial-check.png) 25 262. Click the dustbin icon as shown below to disable the terminal using the serial port. 27 28 **Figure 3** Disabling the terminal using the serial port 29 30 ![hi3516-faq-serial-close-terminal](figures/hi3516-faq-serial-close-terminal.png) 31 323. Click **Burn**, select the serial port, and start burning images again. 33 34 **Figure 4** Restarting the burning task 35 36 ![hi3516-faq-serial-reburn](figures/hi3516-faq-serial-reburn.png) 37 38 39## The development board failed to connect to the PC 40 41- **Symptom** 42 43 The file image cannot be obtained after a serial port is selected to start image burning. 44 45 **Figure 5** Failed to obtain the file image due to network disconnection 46 47 ![hi3516-faq-network-fail](figures/hi3516-faq-network-fail.png) 48 49- **Possible Causes** 50 51 The development board is disconnected from the PC. 52 53 Windows Firewall does not allow Visual Studio Code to access the network. 54 55- **Solution** 56 571. Check whether the network cable is properly connected. 58 592. Click **Windows Firewall**. 60 61 **Figure 6** Network and firewall settings 62 63 ![hi3516-faq-firewall-setting](figures/hi3516-faq-firewall-setting.png) 64 653. Click **Firewall & network protection**, and on the displayed page, click **Allow applications to communicate through Windows Firewall**. 66 67 **Figure 7** Firewall and network protection 68 69 ![hi3516-faq-firewall-setting-allow](figures/hi3516-faq-firewall-setting-allow.png) 70 714. Select Visual Studio Code. 72 73 **Figure 8** Selecting Visual Studio Code 74 75 ![hi3516-faq-firewall-find-vscode](figures/hi3516-faq-firewall-find-vscode.png) 76 775. Select the **Private** and **Public** network access rights for Visual Studio Code. 78 79 **Figure 9** Allowing Visual Studio Code to access the network 80 81 ![hi3516-faq-firewall-vscode-allow-network](figures/hi3516-faq-firewall-vscode-allow-network.png) 82 83 84## (Hi3516) No information is displayed through the serial port 85 86- **Symptom** 87 88 The serial port shows that the connection has been established. However, no information is displayed through the serial port after the board is restarted and **Enter** is pressed. 89 90- **Possible Cause 1** 91 92 The serial port is connected incorrectly. 93 94- **Solution** 95 96 Change the serial port number. 97 98 Start **Device Manager** to check whether the serial port connected to the board is the same as that connected to the terminal device. If the serial ports are different, correct the serial port number by following instructions in ["Error: Opening COMxx: Access denied" is displayed when I start image burning](#error-opening-comxx-access-denied-is-displayed-when-i-start-image-burning). 99 100- **Possible Cause 2** 101 102 The U-Boot of the board is damaged. 103 104- **Solution** 105 106 Burn the U-Boot. 107 108 If the fault persists after you perform the preceding operations, the U-Boot of the board may be damaged. You can burn the U-Boot by performing the following steps: 109 1101. Obtain the U-Boot file. 111 > ![icon-notice.gif](public_sys-resources/icon-notice.gif) **NOTICE** 112 > 113 > You can download the U-Boot file from the [open-source package](device\hisilicon\hispark_taurus\sdk_liteos\uboot\out\boot\u-boot-hi3516dv300.bin). 114 1152. Burn the U-Boot file. 116 117 Follow the instructions in [Burning Through the USB Port](https://device.harmonyos.com/en/docs/documentation/guide/upload_hi3516_small_system-0000001326267405). 118 1193. Log in to the serial port after the burning is complete. 120 121 **Figure 10** Information displayed through the serial port after the U-Boot is burnt 122 123 ![hi3516-faq-burn-uboot-success](figures/hi3516-faq-burn-uboot-success.png) 124