i like the 12v source under the power plug you can use the one from the dvd drive if you like

under the fan plug there is 3 little tips sticking out or 4 if ur fans have 4 plugs make a bridge of solder to the 2 5v prongs if you have the one with the 3 prongs its the outside 2 if you have 4 of em just connect the red and the brown

once your done with that test it before putting it all back together and if all is well put some hot glue on the connectiongs to pervent them from rattling off or grounding out this is what it will look like when ur done

now put everything back together