No power?

I shut down my pc a few days ago. The next day i restarted it and i got nothing. no fans, no drives, nothing, its like i didnt press anything at all.

I opened that sucker up and the green light on the mobo was on. there was no smell of anything burning but i swapped out the psu and disconnected the modem (the only card attached to the system). i still had the same luck. i switched cases thinking it might be the power button on the case, still nothing. all the connections are fine so i dont know what it is. hopefully you guys can help me out. thanks in advance.

make sure the system speaker is attached..any beeps?

if there is a NIC try removing it (you mentioned a modem)

try removing/replacing the battery...

speakers are attached but i get nothing. there is no nic card and i replaced the cmos battery. would the mobo be dead even if the green light is on?

it does not bode well for the mainboard...you might try removing all the drives (hard and optical) and seeif it posts anything...

also, you might try removing the memory modules to see if you can at least induce a beep

remove the RAM sticks, clean the connectors and re-seat.
remove the CPU, clean, and reseat - IF you have heat sink goop handy..otherwise skip this step.

remove the two IDE headers, and the floppy header from the mobo

now try...