Possibly fried mobo? weak psu?

[roarixer]

hey got an issue, not particularly adept at pcs but ill post what tests ive tried to run

tried to install a wd500gb slave hd yesterday
booted up fine and then about to format at disk management (/w Win7)
as soon as i clicked 'ok' to begin formatting, pc shuts down

i got kind of worried at this stage so i ran a series of tests
computer can turn on but turns off after 6-7s and no display
the next morning, the computer remains turned on but no display
so i guess the psu is fine, or it is really weak

after i thought maybe my old hd was fried so i plugged the new hd as master drive but same result

i did notice the fan on top of the mobo heatsink was running slow, if not, not running at all so maybe the mobo might be fried?

thanks for your input!
i appreciate it

p.s. i want to add that i tried running without any hd plugged in and same result occured (pc turns on but no display)

 

[saaiello]

check all connections and make sure nothing is grounded out if i was you id disconnect everything inside and then reconnect makeing sure everything is tight and seated properly also while you are doing this it is good practice to bundle all unused wires with a tie wrap and keep all wires together.