Computer won't start up

So my computer won't start and i just replaced the power supply upon my friends advice (the computer expert ) and now i don't know where to start, the led on the mother board and back of the computer are on but the button on the case won't do jack shiet and nothing happens when i push it. Help? anyone?

 

hi, assuming that your power connector from the switch is connected to the right place make sure the main power connector or connectors are properly seated. some motherboards use 20 pins and some use 24 pins with a second 4 pin connector. make sure you got the right one as some power supplies have several 4 pin connectors that look alike but are not wired the same.

 

You do not give many details so if you can tell us a little more,What is the make and model of your motherboard (if you look at it in the case it is normally on there) what is the PSU that you have installed.

Firstly i would go with the previous post and check that the connections are seated properly (they are the white ones) most PCs use 2 connections a 20 or 24 pin and then on another part of the mobo is a place for a 4 pin these are also white.

Edit Also you say the led lights up,check if there is a reset button on the mobo ?