8 pin connector necessary?

hello. i just bought a pc, i build it my self. it was my first build so it took me some time. the thing is...when i press the power on it doesnt start, the green light on mobo is on (correct me if im wrong. it means that everything is connected!? But one thing i am not sure that is connected properly. my mobo has 8 pin connector for cpu and in the manual it says 'dont forget to plug 8 pin plug' but cable from psu is 4 + 4 pin and i can plug only one 4 pin connector, the other one doesnt fit. could this be why it doesnt start? i have asus m5a99x evo r2.0, fx 8320, gx 550w psu. thank you.

well you need to plug in both 4 pins and they should fit. because those connectors are the same, yellow black wired.  you have to look at the nodge, and the clips, it only fits one way.

No it rly can't fit. do u know if there is any converters that can convert those two 4 pins into 8 pin? here is how plugs look like

After looking at Electrodroid, it appears that the top 2/4 connectors do the same thing, to take the power to the motherboard. Likewise the bottom 2/4 do the same thing, act as a ground. Therefore I assume the only reason for the different shaped connections is to make sure that the connection is made the right way up.

Unless I am mistaken the hexagon connector will fit in the square connector, but obviously not the other way around, I am not sure why one of the 4-pin connectors was made this way, but like I said, it still should fit so long as it is the right way up.

8 pin is plugged in now but it doesnt start. maybe the psu is bad even if the green light is on

what happen when you push the power button? no fans spinning at all? did you connect the front panel header correct?

when the power is pushed nothing happens, well sometimes light on power button blinks when pushed, fans don't spin at all. i tried connecting front panel to my old system and it works so nothing wrong with that.


to me its wierd wenn the led on the mobo is green, standby if you connect the frontpanel connector correct,  i mean power switch reset switch HDD led pwr led. and you push the bottom, that the cpu fan is not spin at all. reseat the 20 +4 pin ATX power connector, and the 2x 4 pin cpu power connectors.  notice that your cpu 4+4 pin connectors are allways yellow black wired!! because you psu has also a  third 4 pin connector that needs to be connected next to the 20 pin atx connector  20+4 pin. but this is a diffrend color wired connector.

please take a picture from your connections, and post it in here!

if the fans not spin at all, and everything is connected correctly, then i personaly think a dead mobo.

ok i reconnected all and it didn't work, so i tried psu on old system - it worked, then i connected again new one exactly the same like before and it worked perfectly. dunno what was wrong before!

Than You very much on help. <3

thats great good luck ☺ would be cool to see some pictures from your build ☺

update: actually i did not connect everything the same, i forgot to plug in usb 3.0 from front panel to motherboard...that's why it actually started lol. Had to install drivers before connecting usb 3.0. pics comming soon :)



cpu fx8320

gpu msi gtx660

mobo m5a99x evo r2.0

ram geil oc17000 2x4gb 2133mhz

cooler hyper 212 evo

psu gx 550w 80+ bronze

case silencio 550

i am ready for battlefield :)

Looks very nice ☺