xbox 360 s when turns on nothing runs then turns off

the xbox 360 slim just activates and then turns off. the cooling fan doesn't start up either.i have used several xbox 360 power cables and all still work with other systems, I have used other push to start face plates from working systems. I still had the same results and I have tried researching the problems but everyone else has no idea either. I also tried to look for maybe a short in a compasiter or a fried terminal but still nothing.