power supply shuts down when CPU cable connected

[mrcashback]

I have an msi xpower x99ac motherboard, and the computer was running fine... Then, as the missus reports "i was just watching a movie and it turned off and wont come back on".... I take a look, and the power button is illuminated but it wont POST. i cleared the cmos and did a complete discharge (for no good reason, just fiddling) to no avail.

Next, I test the power suply by shorting the on wire to ground and it doesnt fire up. Aha, i found the problem (or so i thought) and $200 bucks later I have a new poeer supply.... I hook it up, hit the on button and nkthing happens!.... Ok, back to the drawing board.... I test the old power supply in another room and it fires up.... Could the new power supply be dead Too i wonder and the old one on the fritz?... Well, I started unplugging cables and as soon as i unplugged the CPU cable, it fired up....
Ok, this means something....
I connect everything else and it fires up fine, but as soon as i plug the cpu cable back in the power supply shuts down...

There was no overclocking on this thing, everything bog stock and just over a year old..... So, how to proceed testing further? Am i looking at a motherboard fault or a cpu fault is what i need to know, but how can i identify it?

 

[Mark_1970]

I have an msi xpower x99ac motherboard, and the computer was running fine... Then, as the missus reports "i was just watching a movie and it turned off and wont come back on".... I take a look, and the power button is illuminated but it wont POST. i cleared the cmos and did a complete discharge (for no good reason, just fiddling) to no avail.

Next, I test the power suply by shorting the on wire to ground and it doesnt fire up. Aha, i found the problem (or so i thought) and $200 bucks later I have a new poeer supply.... I hook it up, hit the on button and nkthing happens!.... Ok, back to the drawing board.... I test the old power supply in another room and it fires up.... Could the new power supply be dead Too i wonder and the old one on the fritz?... Well, I started unplugging cables and as soon as i unplugged the CPU cable, it fired up....
Ok, this means something....
I connect everything else and it fires up fine, but as soon as i plug the cpu cable back in the power supply shuts down...

There was no overclocking on this thing, everything bog stock and just over a year old..... So, how to proceed testing further? Am i looking at a motherboard fault or a cpu fault is what i need to know, but how can i identify it?

Notice that board has a 8 pin eps and a 4 pin eps, how do you plug these?

 

[mrcashback]

I have the 8x pin connected to the psu, but no 4x pin

 

[Danielrocha08]

I have an msi xpower x99ac motherboard, and the computer was running fine... Then, as the missus reports "i was just watching a movie and it turned off and wont come back on".... I take a look, and the power button is illuminated but it wont POST. i cleared the cmos and did a complete discharge (for no good reason, just fiddling) to no avail.

Next, I test the power suply by shorting the on wire to ground and it doesnt fire up. Aha, i found the problem (or so i thought) and $200 bucks later I have a new poeer supply.... I hook it up, hit the on button and nkthing happens!.... Ok, back to the drawing board.... I test the old power supply in another room and it fires up.... Could the new power supply be dead Too i wonder and the old one on the fritz?... Well, I started unplugging cables and as soon as i unplugged the CPU cable, it fired up....
Ok, this means something....
I connect everything else and it fires up fine, but as soon as i plug the cpu cable back in the power supply shuts down...

There was no overclocking on this thing, everything bog stock and just over a year old..... So, how to proceed testing further? Am i looking at a motherboard fault or a cpu fault is what i need to know, but how can i identify it?

Notice that board has a 8 pin eps and a 4 pin eps, how do you plug these?

I'm having the exact same issue. The old PSU I have has the "whine" noise, so when i exchanged it with a brand new one(connected everything exactly like I took the old one out) and it will turn on for a few moments then shut off. I have a MSI 970 MOBO and the new PSU is a rosewell 750 extreme. The older PSU was some shit no name brand iBuyPower puts in PCs. (doing this for a friend). the Mobo has an 8 pin spot on but the previous PSU used only the 4 pin. Should I try to connect the 8Pin to see if that works?