Microcontroller dead

[Fistel]

Morning everybody

The microcontroller on my nucleo board NUCLEO-H755ZI-Q is dead after i have used 5V external power to supply it. I don't understand why

[Uwe Bonnes]

Read the data sheet and understand "Maximum ratings" Applying 5 Volt to an FT pin when the chip is unpowered will kill the chip as applying 5 Volt to a TT pin when powered.

[Fistel]

Thanks

Please, what mean "FT pin" and  "TT pin" ?

[Uwe Bonnes]

Have a look at the datasheet table "Legend/abbreviations used in the pinout table"

[Techn]

On which pin or connector did you apply 5v? Try to connect to usb, and see if its getting detected by cube programmer. 

[Uwe Bonnes]

If the MCU heats up fast, it is broken. Been there, done that 8-)

[Fistel]

I use pin 6 on CN11 to apply 5V, on JP2, pin 5 and 6 are connected.

There is no détection on cube programmer.

In the last program i loaded on nucleo board, i make LED yellow and green blinking. But they don't blink any more when the board is supply

[Fistel]

The MCU doesn't heat