PC in boot loop, no BIOS. Gigabyte mobo

[Fugalism]

As of this morning, my PC refuses to boot. The MOBO lights come on and it powers up for a few seconds, then shuts off and attempts to reboot.

The fan lights don't power up, and no BIOS screen shows up. So far I've tried every possible combination of RAM sticks.

I have noticed that without RAM the PC immediately restarts, while taking a few seconds to restart with RAM.

Specs: Intel Core i7-5820k

Gigabyte X99-Gaming 5P

16GB 4x4GB DDR4 2800

Nvidia GeForce GTX960

Samsung Pro Evo 256GB SSD

A WD internal 2TB HDD.

Corsair CX 500 PSU.

I've also tried booting without any USB cables plugged in, without the SSD/HDD plugged in and without the GPU plugged in. I have not made any recent hardware changes, so I have no idea why this is happening all of a sudden. PC worked fine yesterday when I shut it off.

One other thing I noticed, the LAN lights only light up for a brief second once I plug the power in. Normally, those lights stay on regardless of the PC being booted.

I flashed the BIOS using the white usb port to both the F20 and F22 versions. This made the back case fan run, which previously wasn't the case. I still get the boot loop however. This build isn't even 3 months old so I'm at a loss as to what might cause this. Other than the occasional freeze, which I credited to an old HDD, this PC ran fine. Being able to flash the BIOS should mean the mobo is fine, right?

 

[Mr.Scott]

What PSU?

 

[Fugalism]

What PSU?

Corsair CX 500, forgot to include that.

 

[Mr.Scott]

How old?
Because it's borderline acceptable for your system.

 

[trents]

So I'm not clear on whether or not the problem appeared before or after flashing the bios to a newer version. In other words did you start flashing the bios to correct this problem or did the problem occur as a result of the flash?

If the problem was occurring before you attempted to flash the bios I would first look at the PSU as being the problem. Try the PSU in a different computer or swap it with another PSU that is known to be a good one. As Mr. Scott said, the CX Corsair line is not their best and is not generally the choice for high end workstation systems like yours.

The other most likely component is the motherboard.

 

[Fugalism]

How old?
Because it's borderline acceptable for your system.

3-4 years old, which is why I'm also thinking it's more likely to be broken than the mobo. I've got a new PSU coming in today, hopefully that'll be the issue.

- - - Updated - - -

So I'm not clear on whether or not the problem appeared before or after flashing the bios to a newer version. In other words did you start flashing the bios to correct this problem or did the problem occur as a result of the flash?

If the problem was occurring before you attempted to flash the bios I would first look at the PSU as being the problem. Try the PSU in a different computer or swap it with another PSU that is known to be a good one. As Mr. Scott said, the CX Corsair line is not their best and is not generally the choice for high end workstation systems like yours.

The other most likely component is the motherboard.

I flashed the BIOS in an attempt to fix the issue, as it was mentioned on the Gigabyte forums to fix X99 boot loops. The flashing itself worked as described in the manual, which makes me think the mobo is fine. I have a new PSU coming in later this day, which will hopefully fix this.

 

[Fugalism]

Well I've tried a brand new PSU and tried reseating the CPU but I still get the same old boot loop. I think it's time to admit the mobo is done for.

 

[trents]

Well I've tried a brand new PSU and tried reseating the CPU but I still get the same old boot loop. I think it's time to admit the mobo is done for.

Agreed.

 

[wingman99]

Did you try one stick of memory also reseating all the memory? Did you try clearing the CMOS?

 

[macexperts]

Fugalism - did you RMA the board and did this fix the problem? Also have a board that is allowing Qflash update to BIOS but is stuck in same boot loop cycle - I've seen lots of posts on this but many with no follow up.
Would like to know what you found out and was it indeed a MOBO issue? Thanks, all the best