Skr 1.4 turbo doesn't work when the terminal power is connected

when powered from 12v psu it doesn't respond
It used to work but after some flickering in the electricity it is not anymore
but it respond when powered from usb terminal
please help me fix this

... most likely the +5V-regulator on the board is burnt - so it will work only, if powered per USB ...

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Viktor
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thank you for keeping up with me at this point I really appreciate it
Countiuing our root cause to my board's problem
I discovered that the fuse that is responiple for the 5v is blown
changed it with a new one and started testing once the power is on smoke is coming near the fuse
I wonder what is it
and I find it is a little chip called S1A
here is the schematic of that circuit
I wonder what is it's use for the circuit
now that i have to replace it , will it have any affect on the operation of the circuit if I just remove it without putting a new one in ?