acdc_stby

Hello. help solve problem ACIN_DET: 5V 5VSB: 5V Available ACDC_STBY - 0V Accordingly, 12V does not arrive on the board. There are 5.5V and 3.3v on the button. when 5VSB - 5V are shorted ACDC_STBY appears 12V Of course, there is no indication of the button. Tell me how to check the button itself...