Computer not turning on, Please help!

Ok, i just built my computer i was messing with the hard drives and the BIOS settings, i had one hard drive all connected and as the computer was on (i didnt realise) i plugged in the power cord into my second hard drive. it sparked a little and the system turned off, now it wont turn back on and im freaking out. did i break something? will it turn on again? will i have to buy new parts? if you can help please do, thank you.