Question Two separate but identical builds - same motherboard power problem

[Melquiedes]

My friend and I are building two versions of the same build, one for each of us. We can't get the board to power on beyond the board lights glowing when we flip the power. We tried to trip the PWR connectors but nothing works. GPU won't turn on, fans still won't spin and the rig won't POST. Here are the details so far:

We are using a Gigabyte Z390 Gaming X motherboard, an Intel i7-8700K, 16GB of DDR4 RAM (tried 3 different versions), and Nvidia Gigabyte 2080/EVGA 1070 graphics cards. Our power supply is a Corsair TXM Series TX750 watt 80+ gold certified semi-modular PSU.

We have insured everything is properly plugged in (8-pin, 24-pin, CPU seated correctly, etc.) We have tried different CMOS batteries. We have tried 3 different types of RAM - 2 of which are on the QVL but all are at higher speeds (3000-3200 MHz) than the board can fully utilize at stock settings (2666 MHz). That shouldn't be an issue though as it would just run at the highest frequency it can handle, We tried using only one stick at a time. The GPUs works flawlessly in other systems.

It is worth mentioning, however, that the MOBO has a 2x4 CPU power header as well as a 2x2 CPU power header right next to it. Our PSU did not come with a separate 2x2-pin (ATX_12V_2X2) cable for the CPU power, just the standard 2x4 (this comes out of the same non-modular port of the PSU as the 24-pin, so it's safe to assume this is the correct cable.) In my research it seems that the 2x2 port is optional and meant for OCing, but maybe not here? I don't have any dedicated 2x2 cables, but I do have a 2x3 cable that I can fit into the 2x2 header. I'm hesitant to try and power on with a modular 2x3 cable plugged into a 2x2 header, though.

Because we're both having the same problem, I'm inclined to believe it is user error and not a parts issue. But at the same time, I've run out of ideas. Maybe I'm too close to it and hopefully someone with an outside view might think of something.

 

[Ralston18]

Update your post to include full hardware specs including PSU(s) and OS.

Do you have the motherboard manual? If not, here:

http://download.gigabyte.us/FileList/Manual/mb_manual_z390-gaming-x_v1_e.pdf

Verify that I have indeed found the applicable manual.

Check your power connections per Pages 12 -14.

Also look at the overall power configuration per Section 2-8, Page 37.

Focus on just one build. Once that build is working/turning on then try the same settings on the other build.

 

[Melquiedes]

Update your post to include full hardware specs including PSU(s) and OS.

Do you have the motherboard manual? If not, here:

http://download.gigabyte.us/FileList/Manual/mb_manual_z390-gaming-x_v1_e.pdf

Verify that I have indeed found the applicable manual.

Check your power connections per Pages 12 -14.

Also look at the overall power configuration per Section 2-8, Page 37.

Focus on just one build. Once that build is working/turning on then try the same settings on the other build.

Thanks for the reply. Updated to include the PSU model. No OS yet since we haven't been able to POST or even install Windows 10. That is the correct manual and it seems I have done everything correctly.

It is worth mentioning however, that my PSU did not come with a separate 4-pin (ATX_12V_2X2) cable for the CPU power in the top left of the motherboard, just the standard 2x4 (this comes out of the same non-modular port of the PSU as the 24-pin, so it's safe to assume this is the correct cable.) In my research it seems that the 2x2 port is typically optional, but maybe not here? I don't have any dedicated 2x2 cables, but I do have a 2x3 cable that I can fit into the 2x2 header. I'm hesitant to try and power on with a modular 2x3 cable plugged into a 2x2 header, though.