Strange behavior - HW probelms?

[TheRaprus]

Hello to everyone.

I'm working on a display interface, changing from M3 -> M4 -> H5 CPUs. The issue appeared on all type(it's a HW issue?)

At the beginning I can connect, debug, program and so on. Bt after some operation, I can't continue. I still have a "No STM target found" error, from CubeIDE and Programmer.

What I can see is that the CPU voltage is not 3.3V, but less:

This happen with different STLINK-V2 or V3. Obviously I check the volts on SWD pin 1 and it's always ~3.3V

When this happen I usually pas to another board/JTAG. But afer a while I connect the old JTAG-Board and it work again. I enclose the schematics, because I presume it's a HW problem.

Can someone gimme a tip?

Thanks.

[TheRaprus]

Hello to everyone.

I'm working on a display interface, changing from M3 -> M4 -> H5 CPUs. The issue appeared on all type(it's a HW issue?)

At the beginning I can connect, debug, program and so on. Bt after some operation, I can't continue. I still have a "No STM target found" error, from CubeIDE and Programmer.

What I can see is that the CPU voltage is not 3.3V, but less:

This happen with different STLINK-V2 or V3. Obviously I check the volts on SWD pin 1 and it's always ~3.3V

When this happen I usually pas to another board/JTAG. But afer a while I connect the old JTAG-Board and it work again. I enclose the schematics, because I presume it's a HW problem.

Can someone gimme a tip?

Thanks.

[STTwo-32]

Hello @TheRaprus 

When You find a solution to your own request, is a good idea to share it instead of deleting your post. It may help others.

Best Regards.

STTwo-32

[Andrew Neil]

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@TheRaprus wrote:

At the beginning I can connect, debug, program and so on. Bt after some operation, I can't continue. I still have a "No STM target found" error, from CubeIDE and Programmer.

---

Are you disabling (or re-configuring) some or all of the debug pins at some point in your code?

[TheRaprus · Accepted solution]

You're right!

But after posting my colleague realize that a cable isn't well inserted. It's a mistake, after 2-3 month of tests.
And I'm sure I can't realize it until I made this post ☹️

[Andrew Neil]

So you were right - it was a hardware problem!