Xbox 360 slim no power

I just picked up a 360 slim and it wont turn on. I hit the button and it makes the sound thst it should when it turns on but wont boot. Usb ports looks fine and the inside is very clean. Could it be the power brick? A short somewhere? Ive also heard a small copasitor on the front next to the power button could be the issue. HELP!

I know there’s a certain set of resistors that can go wrong that control heating, (sensor) thus booting then turning off possibly this is the problem I assume your willing to open up the Xbox, get a eletronic tester for the resistors and get advice or a manual for what section is for what purpose then test all of them with the electronic tester, good luck and I can show you my Xbox 360 s for reference if you want I already have takes it apart before