nRF Connect Error "NRF_ERROR_TIMEOUT"

[Alaa]

I plugged my nRF52 evaluation board to PC using a micro USB cable, dragged a ble_peripheral hex file from Nordic examples to the mounted JLINK drive, started up nRF Connect v2.2.1, launched Bluetooth Low Energy app, chose the recognized COM port, confirmed the message suggesting to program the kit with the required firmware, then I get this error:

10:28:35.9290 Connectivity firmware version 1.2.1 detected
10:28:35.9350 Opening adapter connected to COM39
10:28:36.4700 Successfully opened COM39. Baud rate: 1000000. Flow control: none. Parity: none.
10:28:36.4730 Reset performed on adapter COM39
10:28:38.4770 Error occured when opening port. Errorcode: NRF_ERROR_TIMEOUT (0xd)

Environment:
Windows 7
nRF Connect v2.2.1
PCA10040, V1.2.1
Tried hex file: ble_app_uart_s132_pca10040.hex , ble_app_alert_notification_s132_pca10040.hex

Thanks

[Alaa]

Nordic provides compiled hex examples. Such as ble_app_alert_notification. And to burn it on the board you can drag it to the mounted drive. And then you should be able to connect to it with nRF Connect. I find the board with another Bluetooth device (smartphone) and I can connect to it. But nRF Connect keeps failing when I choose the COM port