1# Fixing Burning Issues 2 3 4## What should I do if Error: Opening COMxx: Access denied is displayed when I start burning 5 6- **Symptom** 7 8 Error: Opening COMxx: Access denied is displayed after clicking Burn and selecting a serial port. 9 10 **Figure 1** Failed to open the serial port 11 12  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  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  31 323. Click **Burn**, select the serial port, and start burning images again. 33 34 **Figure 4** Restarting the burning task 35 36  37 38 39## What should I do when Windows-based PC failed to be connected to the board? 40 41- **Symptom** 42 43 The file image cannot be obtained after clicking Burn and selecting a serial port. 44 45 **Figure 5** Failed to obtain the file image due to network disconnection 46 47  48 49- **Possible Causes** 50 51 The board is disconnected from the Windows-based 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  64 653. Click **Firewall & network protection**, and on the displayed page, click **Allow an app through the firewall**. 66 67 **Figure 7** Firewall & network protection 68 69  70 714. Select Visual Studio Code. 72 73 **Figure 8** Selecting Visual Studio Code 74 75  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  82 83 84## What should I do when the image failed to be burnt? 85 86- **Symptom** 87 88 The burning status is not displayed after clicking Burn and selecting a serial port. 89 90- **Possible Causes** 91 92 The IDE is not restarted after the DevEco plug-in is installed. 93 94- **Solution** 95 96 Restart the IDE. 97 98 99## What should I do if no information is displayed through the serial port? (Hi3516) 100 101- **Symptom** 102 103 The serial port shows that the connection has been established. After the board is restarted, nothing is displayed when you press **Enter**. 104 105- **Possible Cause 1** 106 107 The serial port is connected incorrectly. 108 109- **Solution** 110 111 Change the serial port number. 112 113 Open Device Manager to check whether the serial port connected to the board is the same as the serial port connected to the terminal. If they are different, change the serial port number by following the instructions provided in " Error: Opening COMxx: Access denied". 114 115- **Possible Cause 2** 116 117 The U-Boot of the board is damaged. 118 119- **Solution** 120 121 Burn the U-Boot. 122 123 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: 124 1251. Obtain the U-Boot file. 126 127 >  **NOTICE** 128 > The U-Boot file of the two boards can be obtained from the following paths, respectively. 129 > 130 > Hi3516D V300: device\hisilicon\hispark_taurus\sdk_liteos\uboot\out\boot\u-boot-hi3516dv300.bin 131 > 132 > Hi3518E V300: device\hisilicon\hispark_aries\sdk_liteos\uboot\out\boot\u-boot-hi3518ev300.bin 133 1342. Burn the U-Boot file by following the procedures for burning a U-Boot file over USB. 135 136 Select the U-Boot files of corresponding development boards for burning by referring to [Burning to Hi3516D V300](https://device.harmonyos.com/en/docs/documentation/guide/ide-hi3516-upload-0000001052148681)/[Burning to Hi3518E V300](https://device.harmonyos.com/en/docs/documentation/guide/ide-hi3518-upload-0000001057313128#section93591711580). 137 1383. Log in to the serial port after the burning is complete. 139 140 **Figure 10** Information displayed through the serial port after the U-Boot file is burnt 141 142  143