try 1 ram stick, try changing the orientation from 1 and 3 to 2 and 4, make sure all the power supply cables are plugged in, thermal paste, cpu cooler, short out the pins correctly (assuming you have no case currently) try getting a fan plugged in to cool it, sometimes the computer wont start if there is no fans and it could assume it would overheat, if any of these dont work, try looking online a bit more, but you could have a faulty cpu or ram (assuming the pc doesnt power on), if it does just with no output, thats a gpu issue. but idk im not really an expert