For paperclip test, you need to unplug PSU from everything its attached to. Then, if you have a casefan that connects using 4pin molex connector, or an adapter to covert it, hook it up by itself to PSU, even 2 fans if you choose. This way, if the test works the PSU fan and casefans should spin normally. Anyways, for the procedure...you need to take one end of a paperclip and wedge into Green wire connector (PS_ON)on main 24pin power connector. Take the other end and plug into an adjacent black wire connector(ground). After that, plug in PSU to AC outlet, flip PSU power switch and fans should turn on. If this doesn't work, the new PSU is probably bad. If it works, I'd suspect the motherboard.