Stlink v3 minie problem

[zsx]

Hello everyone. I had some interesting issues with my stlink. I was debugging just fine for about 2–3 weeks, but yesterday i was unable to debug for several reasons: target under reset, cannot erase flash. But after a few hours, everything became fine again. Today the same problem occurred, i changed MCU, and it didn't work. St link was a little bit warmer than usual. Then i tried debugging using other st link and everything was fine again. It was a custom board which has power from meanwell power supply.
So my question is can this problem be caused by grounds from pc and power supply? Another idea i had is that i shorted stlink when it was on my desk by accidentally touching something. What do you think?

[AScha.3]

Hi,

ESD / static discharge ... damage sometimes "surprisingly" fast . :)

And not always full kill , some chips just get  warm, but still work (some time or sometimes...).

And just from my experience : the st-linkV3 is very sensitive to ground connection and the "spikes" coming from mains. I had no luck with debug for more than some seconds or minutes, until i connected everything (PC , scope and supply to target ) to the same / only one  mains outlet. Now ok, most time. Try this...

[zsx]

So grounds shouldnt be a problem? Now im thinking about v3 or isolated v3, but isolated is a bit expensive

[AScha.3]

I wrote : And just from my experience : the st-linkV3 is very sensitive to ground connection

You : So grounds shouldnt be a problem?

???

-> connect everything (PC , scope and supply to target ) to the same / only one  mains outlet. 

Try this...

+

> isolated v3, but isolated is a bit expensive

Right, i think same,  so i dont have this and cannot tell about better or not .