After flashing done and removing jtag, our application is not working

[GAGGA.1]

I am using STM32F439NIHx MCU. After flashing the code, I removed ST-Link V2 from my PCand restart the MCU but our application is not working. But if I connect ST-Link V2 to my pc then my application is working. What is this problem? Please suggest any solution.

[Tesla DeLorean]

Make sure BOOT0 is pulled low.

Find a UART to use for debug output.

Instrument HardFault_Handler and Error_Handler so it doesn't die silently.

Identify any other infinite while loops that you have, and instrument those or make sure the end up in the Error_Handler and identify the file/line of failure.

Lacking a USART, find a GPIO or LED you can use to signal reaching certain checkpoints or failures.

Enable USART/GPIO in Reset_Handler if failures occurs early in the boot process.

Check supplies and VCAP voltage/capacitors.

Check NRST line.​

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[GAGGA.1]

Thanks for your answer.

We have to remove emulator form JTAG port then it is working absolutely working fine.