Mobo only boots with 4 pin cpu connector (in 8 pin slot)

[RealityLoop]

 My msi z97 gaming 5 mobo has an 8 pin cpu power slot, but my board only powers on when I use a 4 pin connector in that slot to power the cpu. When I do this the board powers on and q codes get all the way to 99. Haven't tried it with anything else connected besides my 2x samsung evo 250gb ssds though.

 

The cpu slotted atm is an i7-4790k running stock.

 

If I use an 8 pin to try and power it the board just turns on for a second and shuts right back off. Not sure why that is but it happened on my last motherboard as well (asus rampage iv black edition w/ an i7 4820k @ 4.6 ghz).

 

I was using the same psu then as I am now, it's a +12v single rail rosewill photon 1200w modular psu.

 

I don't know why i decided to do this but to get these boards to work I took a cord that has an 8 pin connector on one end / and a 4+4 pin connector on the other end and snipped off half of it so that its just a 4 pin on each end now. The side that plugs into the psu has 8 slots still but 4 are dead because i clipped the wires. 

 

I've read that the only thing gained by using an 8 pin cpu power connector is additional grounding for stability when overclocking so I can't fathom why I can only get my board to power on with a 4 pin! Very confusing to me, please explain if possible.

 

Is this even safe?

 

Thank you all for your time.

[W-L]

-SNIP-

 

Welcome to the Forums!

 

just a tip change the text to automatic since it's unreadable in dark mode.

 

Since you have such a high wattage PSU do you have another 4+4pin cable you can use instead it sounds like possibly a faulty connection made by the cable. And you can run a 4pin on a 8 pin CPU (EPS) connector but it limits you on power so overclocking isn't a good idea if your planning that.

[QueenDemetria]

Thank you all for your time.

You dun goofed. You should not have cut off the other 4 pins on that connector. The 8 pin you are probably trying to use is for the GPU/PCIe cards, which uses a different pinout.

[Godlygamer23]

What eight pin connector were you using? Was it labeled CPU, VGA, or PCIe?

[RealityLoop]

I don't have an extra 4/4 pin connector but this one is labeled pcie lol. None of the other cables that came with the psu would work. I almost went and bought a new psu. Should I figure out where to buy a new 8 pin / 4 + 4 pin cable then?

[Godlygamer23]

I don't have an extra 4/4 pin connector but this one is labeled pcie lol. None of the other cables that came with the psu would work. I almost went and bought a new psu. Should I figure out where to buy a new 8 pin / 4 + 4 pin cable then?

See if Rosewill will send you another one. Since you ruined the one that's included, you will be paying for it.

 

And that explains why the system was shorting. PCIe and EPS/4 pin connectors have different pin-outs.

[W-L]

I don't have an extra 4/4 pin connector but this one is labeled pcie lol. None of the other cables that came with the psu would work. I almost went and bought a new psu. Should I figure out where to buy a new 8 pin / 4 + 4 pin cable then?

 

yeah don't use the PCI-E they are not the same pinout as the EPS connector, your lucky your motherboard didn't fry. Check to see if you can get either an adapter or new cable for that PSU.

[RealityLoop]

Will this suffice?  

Rosewill RCDV-12003 9.8" (250mm) Single Sleeved 8 Pin Motherboard Power Extension Cable M-F

http://www.newegg.com/Product/Product.aspx?Item=N82E16812119482&cm_re=rosewill_single_sleeved_8_pin_motherboard_power_extension_cable-_-12-119-482-_-Product

 

 

 

And W-L I probably did fry my asus mobo by doing this. Worked for 3 months and ended up with q code 5a and a black screen. RMA'd it yesterday

[Godlygamer23]

Will this suffice?  

Rosewill RCDV-12003 9.8" (250mm) Single Sleeved 8 Pin Motherboard Power Extension Cable M-F

http://www.newegg.com/Product/Product.aspx?Item=N82E16812119482&cm_re=rosewill_single_sleeved_8_pin_motherboard_power_extension_cable-_-12-119-482-_-Product

 

 

 

And W-L I probably did fry my asus mobo by doing this. Worked for 3 months and ended up with q code 5a and a black screen. RMA'd it yesterday

You clipped the wires. They're useless now unless you splice them back together.

[W-L]

Will this suffice?  

Rosewill RCDV-12003 9.8" (250mm) Single Sleeved 8 Pin Motherboard Power Extension Cable M-F

http://www.newegg.com/Product/Product.aspx?Item=N82E16812119482&cm_re=rosewill_single_sleeved_8_pin_motherboard_power_extension_cable-_-12-119-482-_-Product

And W-L I probably did fry my asus mobo by doing this. Worked for 3 months and ended up with q code 5a and a black screen. RMA'd it yesterday

 

Oh that's unfortunate, and not that's just and extension cable for an EPS 8 pin, only other thing I can really see working is a PCI-E to EPS adapter like this which repins the wire for EPS:

http://www.amazon.com/6-Pin-PCI-E-8-Pin-Adapter-Length/dp/B007NZDPMU/ref=sr_1_3?ie=UTF8&qid=1449357456&sr=8-3

[QueenDemetria]

I don't have an extra 4/4 pin connector but this one is labeled pcie lol. None of the other cables that came with the psu would work. I almost went and bought a new psu. Should I figure out where to buy a new 8 pin / 4 + 4 pin cable then?

According to this review your PSU has two cables with the 4+4 connectors on them. Since you cut one of the cables, you can use the other unless you cut that off too. You cannot use the PCIe connector though, its a different pinout. If you don't have the other 4+4 cable, then just use the 4 pin, using an adapter will just create a weak point.

 

And please use standard formatting on your text, the orange is hard to read.