rror: No STM32 target found! If your product embeds Debug Authentication, please perform a discovery using Debug Authentication

[Shafnas]

I'm from an institution where we use STM32 as our regular teaching material. But I have noticed that many of our boards are getting this issue, Even though it's physically perfect. This is making a lot of ewaste for us. I have tried all the method searching in Goolge 
(for example: using the reset button while pressing connect)
But all these are not helping us. 
Could you tell me why this are happening and how can I troubleshoot if a board has encountered such an issue. As we are a large customer for this board, this error is causing a lot of fund issue. could anyone help to trouble shoot this.

[Imen.D]

Hello @Shafnas and welcome to the Community,

Make sure to upgrade your ST-Link firmware and check that jumpers on the board are in default position.

Set power on the VDD and check that the target is powered. 

Try following the steps on the following guidelines : How to solve debugger connection issues - STMicroelectronics Community

[Shafnas]

I have tried updating the firmware, and the board also has been powered. I almost tried everything that I couldfind in a basic web search. But still the issue's there.

[Tesla DeLorean]

A Technical Institute? Perhaps you can pull a schematic and check voltages at appropriate circuit nodes?

What Boards are we talking about?

Check ST-LINK connectivity jumpers. Power jumpers? Have you added a jumper for BOOT0 pin?

Boards are not immune to ESD damage or placement on conductive surfaces. Careful handling is necessary.