Question HP Presario C700- Not Turing on- no lights , screen ect- PS socket flash blue for a sec- Motherboard repair question

Sep 10, 2020
Hi, i have the C700 which wont turn on and no lights, screen ect- totally dead- PS is good. Switch is good and 3v there shorting when pressed. When plugged in the blue light at the power socket flashes blue for a sec . PS socket resistance is only 8000 ohms?? Pulled it all apart and 19v is through the input mosfets and sense resistor. So they are turned on by super IO? 3V isnt at bios chip next to super IO if it is the bios chip? no volts on any leg. pulled all parts off board to see if they are causing short or drag down Tried my PS and NO amps are being drawn and with power switch pushed too. Fan dosent twitch. CPU ect are cold as no amps drawn Tried resistance to ground of many parts and cant find any shorts and PS wasnt drawing amps anyway. So slightly ON but not fully. Super IO fault? Also screen disconnected in case that was faulty and 19V is at connector to screen Any one can help , that be appreciated as out of ideas