[SOLVED] PC starts for half a second then turns off. HELP!

[eguest01]

I recently built a new Gaming PC, and It has been working fine for about a month. Just a couple days ago i went to turn it on, it began to start and then the fans and leds abruptly stopped. When i press the power button, the leds light up and the fans spin for anywhere from 0.3s to 1.0s and then completely stop. The LEDs on my RAM stay lit, however. Yesterday i unplugged all the cables from my PC except for the power cable, and it started fine and worked all day. I have been unable to reproduce this startup. The problem now persists after being off all night. This is my second PC build and i was very confident in my ability to build it without error. I am wondering if i have a faulty power supply, or perhaps a faulty motherboard battery? Also, this is my first time using PSU Extention cables so perhaps they are the issue. I am lost, and it really sucks that my brand new build won't turn on. Any help would be greatly appreciated. I will link a video of what the error looks like in real time. Thanks

VIDEO OF ISSUE

PC Specs Below:

CPU: Intel i-7 9700K
GPU: NVIDIA GeForce RTX 2070
RAM: 32GB Corsair Vengance RGB
MOBO: Asus Prime z390-A
HDD: Seagate BarraCuda 2TB Internal Hard Drive
SSD: Samsung 970 EVO 500GB - NVMe PCIe M.2
PSU: Corsair RM 750W CP-9020055-NA
CPU COOLER: NZXT Kraken x52 240mm
PSU CABLES: Antec Power Supply Sleeved Cable Extension Kit
BIOS settings are all default except XMP profile for RAM

 

[OctaBotGamer]

I think it's because of a certain component that isn't allowing to boot, same happened with me, it was my hard drive

 

[InvalidError]

Power turning on and then shutting off almost immediately usually means that something tripped one of the PSU's protections. Make sure there aren't any unused connectors possibly shorting onto something, disconnect all non-essential hardware, make sure all remaining hardware (should only be the motherboard's ATX and EPS connectors) are plugged in correctly and if you still have no boot with that, you may have a dead motherboard. Other things you may want to try before RMAing are swapping PSUs if you have a spare and taking the motherboard out of the case to test whether it may be shorting out to something in the case, such as an IO plate finger sticking into an IO port or misplaced motherboard support stud shorting something on the back.

 

[eguest01]

Power turning on and then shutting off almost immediately usually means that something tripped one of the PSU's protections. Make sure there aren't any unused connectors possibly shorting onto something, disconnect all non-essential hardware, make sure all remaining hardware (should only be the motherboard's ATX and EPS connectors) are plugged in correctly and if you still have no boot with that, you may have a dead motherboard. Other things you may want to try before RMAing are swapping PSUs if you have a spare and taking the motherboard out of the case to test whether it may be shorting out to something in the case, such as an IO plate finger sticking into an IO port or misplaced motherboard support stud shorting something on the back.

Lets hope its not a dead motherboard, that would hurt. I will try these fixes. Thank you very much for your help, I really appreciate it!

 

[e4r33d]

This happens mostly when the ram isnt seated corectly , remove the ram sticks and give them a good press when you put them back in