you saw that the PSU and motherboard fan moved for a second and then stopped .. hmmm
first test the power supply :
remove the PSU from your pc & connect the green wire & any black wire .. it should work .. if it didn't work so that's mean it wasn't fixed ..
if its fan running then it is the mainboard .. check for any shorts with the case ... !
take the motherboard out of the case & connect it to the PSU then test if it will run ..
but the important is to test the PSU first ..
sorry for my bad English ,