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Strange thing happening,

I tried to use ... 345917.pdf

Followed the example guide for step down 12V to 5V. Than, connected LM1117 on the 5V out to get 3.3 and now i have an issue. When i power up the circuit with 12V, everything works until i touch it with probe or some other wire.

The input is 12V 2.5A PSU

What could i do wrong?

p.s. here is the video how it happens


Ah, i noticed something very strange,

if i hold with my fingers the main 12V input (directly on the contacts), and touch some pads with wire in another hand, it doesn't happen :D

Must me some mess with potentials, grounding .. etc...

Any thoughts?
Thank you for your concerns... The issue was the displaced potentiometer on another board.

The resistors have very close ties to chips internal regulations and in this case extracting those wires made confusion in chip so it was shutting down(not being able to boot again) as a protection.

I changed the layout on the PCB so it's great now.
Thnx anyway...