[SOLVED] Brand new PC would turn for a split second and then turns off.

[E30IS]

Hello, I am building a new PC and I am having an issue where the computer turns on for less than a second and then turns off. While it turns, I noticed that the CPU light on the motherboard (EZ debug) turned on with a red light. When I remove the CPU 8-pin power cables that connects to the motherboard, the pc will turn on with the red light on for CPU.

My specs are:
1. AMD Ryzen 3700x 3rd gen
2.MSI MPG X570 Gaming Plus motherboard
3.G.skill ripjaws 32gb ddr4 3600 RAM
4.1tb Hard Drive
5.120GB SSD
6.Musetex Phantom ATX mid tower case
7. EVGA BQ 600 W 80+ Bronze.

What could be the issue as I have replaced the CPU (even though it was brand new) thinking it was defective. The motherboard is brand new as everything else, I have checked the wiring it they all seem to be correct. Anyone faced similar problem?
Thank you in advance.

 

[Archaic59]

Hello, I am building a new PC and I am having an issue where the computer turns on for less than a second and then turns off. While it turns, I noticed that the CPU light on the motherboard (EZ debug) turned on with a red light. When I remove the CPU 4-pin power cables that connects to the motherboard, the pc will turn on with the red light on for CPU.

My specs are:
1. AMD Ryzen 3700x 3rd gen
2.MSI MPG X570 Gaming Plus motherboard
3.G.skill ripjaws 32gb ddr4 3600 RAM
4.1tb Hard Drive
5.120GB SSD
6.Musetex Phantom ATX mid tower case
7. EVGA BQ 600 W 80+ Bronze.

What could be the issue as I have replaced the CPU (even though it was brand new) thinking it was defective. The motherboard is brand new as everything else, I have checked the wiring it they all seem to be correct. Anyone faced similar problem?
Thank you in advance.

Where's the video card? I don't see it listed. You did install one right?

 

[E30IS]

Where's the video card? I don't see it listed. You did install one right?

Sorry i missed it, Its Geforce GTX 1660 ti. But I dont think it has anything to do with my problem because i didnt install it yet, the pc isnt even running lol

 

[Archaic59]

Sorry i missed it, Its Geforce GTX 1660 ti. But I dont think it has anything to do with my problem because i didnt install it yet, the pc isnt even running lol

Some motherboards won't POST without the video card. It depends on how the bios is set up. Install the video card and don't forget to connect the PCIe power cable(s).

 

[E30IS]

Some motherboards won't POST without the video card. It depends on how the bios is set up. Install the video card and don't forget to connect the PCIe power cable(s).

Ok will do..

 

[E30IS]

Some motherboards won't POST without the video card. It depends on how the bios is set up. Install the video card and don't forget to connect the PCIe power cable(s).

Installed it, powered it up, same thing!
When I removed the CPU power cables, the pc would run!

 

[Archaic59]

Installed it, powered it up, same thing!
When I removed the CPU power cables, the pc would run!

You need to go through the checklist posted here-
https://forums.tomshardware.com/thr...ng-about-post-boot-no-video-problems.1285536/

 

[Karadjgne]

What psu cable is being used to attach to the EPS connector on the motherboard? It should be the hardwired 4+4pin with EPS or CPU label, not one of the modular cables.

 

[E30IS]

What psu cable is being used to attach to the EPS connector on the motherboard? It should be the hardwired 4+4pin with EPS or CPU label, not one of the modular cables.

Yes I am using the cable labeled CPU1 and CPU2. Tried to plug in 8 pin CPU1 cable, didnt work. Tried pluging the other 4 pin cable next to it and still same issue.

 

[E30IS]

You need to go through the checklist posted here-
https://forums.tomshardware.com/thr...ng-about-post-boot-no-video-problems.1285536/

I have checked them step by step. Also tried a different PSU, different RAM, checking the manual etc. I feel like its short circuiting somewhere..

 

[Karadjgne]

Gonna hate this but pull the motherboard completely out of the case. Inspect the back for any long/sharp solder points in that area. Also check the case for any pre-installed motherboard standoffs that do not line up with the current holes. Also look for any small burn/scorch marks (they'll look like black dots) where the motherboard tray could have been warped into the back of the mobo. Check all pre-installed case wires and any pass-through that is not rubber grommeted, any wall area where wire could possibly be pinched (like by your drives).

Has to be sorta thorough, especially the cable routing and cables. Those solder points get quite sharp and it's not uncommon for ppl to stuff wires behind the motherboard tray and try and cram the right side panel closed, puncturing the wire insulation or pinching drive power wires.

 

[DSzymborski]

Yeah, as Karadjgne says, check these issues on the back of your motherboard and the case.

I'd take the case completely out of the equation for now. Breadboard this build; try to get it running on something non-conductive like the motherboard box.

 

[E30IS]

Gonna hate this but pull the motherboard completely out of the case. Inspect the back for any long/sharp solder points in that area. Also check the case for any pre-installed motherboard standoffs that do not line up with the current holes. Also look for any small burn/scorch marks (they'll look like black dots) where the motherboard tray could have been warped into the back of the mobo. Check all pre-installed case wires and any pass-through that is not rubber grommeted, any wall area where wire could possibly be pinched (like by your drives).

Has to be sorta thorough, especially the cable routing and cables. Those solder points get quite sharp and it's not uncommon for ppl to stuff wires behind the motherboard tray and try and cram the right side panel closed, puncturing the wire insulation or pinching drive power wires.

Yeah, as Karadjgne says, check these issues on the back of your motherboard and the case.

I'd take the case completely out of the equation for now. Breadboard this build; try to get it running on something non-conductive like the motherboard box.

Thank you guys for helping. I have disassembled the whole build and checked the motherboard as Karadjgne suggested, I didn't find anything suspicious like black dots or burn marks. I will be replacing the mobo as it is the last thing that could be malfunctioning.

 

[Karadjgne]

Did you also check every last inch of wiring, both psu and case for possibly pinched or punctured wires? Did you breadboard the pc (that's cpu, cpu cooler, 1 stick of ram and 2x psu power cables and nothing else) on cardboard? I'd hate to see you go through the entire rma process for a wire that's been pinched.

 

[E30IS]

Did you also check every last inch of wiring, both psu and case for possibly pinched or punctured wires? Did you breadboard the pc (that's cpu, cpu cooler, 1 stick of ram and 2x psu power cables and nothing else) on cardboard? I'd hate to see you go through the entire rma process for a wire that's been pinched.

Thank you for helping. I have found the issue, It was a defective motherboard (probably cpu pins). I have replaced it and now the PC boots up flawlessly

 

[Karadjgne]

Cool!