Why is my computer not turning on?

[atb484]

I built a computer about 3 months ago and now it won't turn on! I think it could be something with the power box because if you put your ear by the power cord connected to the power box, you can hear a buzzing noise. Then when you unplug it, the sound goes away. Can anyone please help me. The computer costed around $1000. Thanks!

 

[Phillip Corcoran]

Try a new PSU.