Why is there voltage loss on the motherboard?

Question

Iron

Hello guys
This is a question for you The
computer was turned on, the light blinked twice
And the computer did not turn on anymore
I checked the motherboard, and when I turn it on, the following happens
When I connect the power supply to it, I check the voltage with a screwdriver, it is there
And as soon as I press the power button - then the voltage disappears, the indicator on the screwdriver goes out . I
checked all the other components, it's in the motherboard, what could it be? Thanks in advance guys

Answer 1

how did you check the power supply? he is the first to take off in case of problems with electricity

Answer 2

Take the pinout of the ATX power connector.
You turn on the network bp. check voltage +5vsb. Check with a tension gauge, not a screwdriver.
Then you close pwr_on to ground and check the rest of the voltages.
Then you look at the pwr_good level.
this is what I mean by checking

Answer 3

Checked
motherboard with
a screwdriver