Question PC turns on then off, only stays on with CPU power cable disconnected

[harrison.c]

Hey guys, I ran into a problem a couple days ago, computer was working absolutely fine, turned it off to go to sleep and woke up next day for the pc to not turn on whatsoever, not the fans or motherboard lights or anything.
I have tried:
-removing ram and using them individually
-resetting cmos
-different PSU
-reseating CPU and heatsink
-unplugging HDD
-removing GPU

I noticed that removing the cmos battery and pressing power, makes the pc start for a second (fans and lights included) then turn off, rather than not doing anything at all, but for it to happen again i'd have to completely unplug from socket and plug back in.
it's worth noting that EZ debug on my motherboard shows CPU lit up too.
ALSO when I unplug the 8-pin CPU power from the mobo the PC WILL turn on and stay on, but obviously got no display or anything haha, but hopefully that helps rooting out the problem.
Thank you in advance, this is driving me mental.

 

[davew1860]

Please post your PC specs if possible.

Did you make any changes to your computer prior to this problem?

It could be a motherboard issue, but we shall see.

 

[harrison.c]

Please post your PC specs if possible.

Did you make any changes to your computer prior to this problem?

It could be a motherboard issue, but we shall see.

FAN- Cooler Master Hyper 212X CPU Cooler

HDD - Toshiba DT01ACA200 2TB 3.5" 7200RPM SATA3 Desktop Hard Drive

PROCESSOR- Intel Core i5 7600K @ 3.80 GHz

PSU- Corsair TX750M 750W 80 Plus Gold Semi-Modular Power Supply

GPU- Gigabyte GeForce GTX 1050 Ti OC 4GB Video Card

Motherboard- MSI B250 GAMING PRO CARBON LGA 1151 ATX Motherboard

SSD- Intel 600p 128GB 80mm PCIE 3.0 X4 M.2 SSD

RAM- Kingston HyperX FURY 8GB (4x 4GB) DDR4 2400MHz



and no changes to the pc no

 

[j.bernard2002]

Hey guys, I ran into a problem a couple days ago, computer was working absolutely fine, turned it off to go to sleep and woke up next day for the pc to not turn on whatsoever, not the fans or motherboard lights or anything.
I have tried:
-removing ram and using them individually
-resetting cmos
-different PSU
-reseating CPU and heatsink
-unplugging HDD
-removing GPU

I noticed that removing the cmos battery and pressing power, makes the pc start for a second (fans and lights included) then turn off, rather than not doing anything at all, but for it to happen again i'd have to completely unplug from socket and plug back in.
it's worth noting that EZ debug on my motherboard shows CPU lit up too.
ALSO when I unplug the 8-pin CPU power from the mobo the PC WILL turn on and stay on, but obviously got no display or anything haha, but hopefully that helps rooting out the problem.
Thank you in advance, this is driving me mental.

I'm having this same problem as i'm typing this.