PS4 1116A no Power,Light, Beep

Hey, first sorry for my english in from Germany :) Have a CUH-1116a received here with the error that they are no longer appealing. Since I only got the motherboard + DriveBoard + cooler + fan I soldered NEN ATX power supply As far as sogut however nothing comes from the PS4 no beep, light or something else not even if I press the EJECT button. Since it is my first PS4 and I want to have this running because they have not run for 1 year in order to xPloit I ask now here if you can give me NEN clue where the problem can be In addition, if I test for passage with the multimeter with + tip on the power button and mass on mass I get out 12v? does it have to be that way or is there a mistake somewhere? I do not have the best now multimeter and suspected of measuring: P Hopefully someone can help me :) Best regards