Computer Won't Turn On (But power LED lights on front are on?)

[rdlp123]

About four months ago my PC would not turn on, but I had no time to fix it because I was off to school once more. Now that I am home for break, I figured I would change the power supply. With the power supply installed, the power LED lights on the front are on, as they would not turn on with the previous power supply. So I thought this would have solved the problem, but when I pressed the power button, the computer simply would not turn on. I have unplugged and replugged all the cords many, many times now, and still the computer will not turn on. The LED lights are still on though. Could it be that the problem just rests with my mother board?

 

[GObonzo]

depends on a lot.

was PC working correctly at any previous time? what happened directly prior to the start of this problem?

what are the system's specs?

do you have enough power to run the system?
do you have case front-panel cables attached correctly to motherboard?
do you have an 8 pin CPU power socket? is the 8 pin power cable securely attached?
are CPU, memory, and other components seated properly? have they been confirmed functional?

 

[rdlp123]

depends on a lot.

was PC working correctly at any previous time? what happened directly prior to the start of this problem?

what are the system's specs?

do you have enough power to run the system?
do you have case front-panel cables attached correctly to motherboard?
do you have an 8 pin CPU power socket? is the 8 pin power cable securely attached?
are CPU, memory, and other components seated properly? have they been confirmed functional?

I had to change the power supply before as well because out of nowhere it smelled like something was burning so I turned the computer off (and would not restart). I changed the power supply and it ran perfectly for three months until I had to leave for school again and stopped working - this is why I changed the power supply again. One day, the computer would just not power on.

The 8 pin is securely plugged in there, as are all the other plugs. To be honest I don't remember much of the system specs:

Windows 7
4 x 3.6 ghz
7770 graphics card
1.5 TB HDD

 

[GObonzo]

...To be honest I don't remember much of the system specs:
Windows 7
4 x 3.6 ghz
7770 graphics card
1.5 TB HDD

what CPU, what Motherboard, what Power Supply?
these can be important in determining what the problem is or helping to narrow down the cause.

worst case: there is a good chance the motherboard or other components were damaged when the original power supply went bad. sometimes it may take a while for the damaged component(s) to actually die for good.
best case: system is configured incorrectly with cables or hardware seated improperly, is not receiving enough power to boot, or something on those lines that can be corrected.