Question New Build Failed - Help Troubleshooting

Apr 26, 2022
10
0
10
Hello All,

I recently put together a new build (poorly it seems). Below are specs.

  • Phanteks 500a DRGB w/ one exhaust fan
  • EVGA 3080 TI Hybrid AIO
  • Intel 12900K with Corsair H115 Elite AIO
  • MSI Z690 WIFI Carbon
  • Samsung 980 Pro 2TB
  • Corsair HX850 Platinum
  • GSkillz TridentZ 6000Mhz 36CL 16x2 (in slots 2 and 4)

I attempted to boot the machine and all fans/lights came on for AIOs and case fans but no input to monitor through DP or HDMI for either onboard Intel UHD or external card. I realized that I didn't plug in the CPU power from mobo to PSU. I plugged in 2x 8 pin connectors to the mobo (one was a 4x4 split) and then to the PSU. Powered on computer and heard a sound that was akin to tires squealing or something getting caught in a fan, however, I could not isolate it and powered computer off. Only the RAM lit up during this power on and down.

At this point, I am presuming the worst but don't want to proceed any further until I get input from others. Any help troubleshooting would be greatly appreciated. I am in the process of taking pictures and will post them soon. Thank you.
 
Apr 26, 2022
10
0
10
XjThMO.jpg


I disconnected one of the CPU power cables (the 4x4) and tried to boot computer. Nothing happens except the RAM RGB initiates. No other lighting or noises except the ethernet port light on the back is illuminated with the cat5 cable plugged in. I'm not entirely sure how to troubleshoot either the mobo or the PSU since I don't have other components to swap? I am on a laptop currently. I have a voltmeter but not entirely sure how to use the thing.
 
Apr 26, 2022
10
0
10
Is the cable you plugged into the CPU connectors on your motherboard labeled CPU? Is the other end labeled PSU? Did you plug it into the PSU slots labeled 4+4 CPU?

I used two cables both labeled CPU. There is no label on the mobo saying "CPU" but the manual says it is the CPU_PWR1&2 slots on the mobo. One cable was included with the Corsair PSU (each end was 8 pin )and one was from an EVGA 750w PSU I had from a previous build (one end was 8 pin and 1 was 4x4). I plugged those two into the part of the PSU slots that say "6+2 PCIE & 4+4 CPU".
 

Phaaze88

Titan
Ambassador
One was included with the Corsair PSU (each end was 8 pin )and one was from an EVGA 750w PSU I had from a previous build (one end was 8 pin and 1 was 4x4).
Welp, looks like we've got a damaged cpu or motherboard - or both.
This gets talked about often in the power supply section of the forum: don't mix cables from other psus - there's no guarantee the pin outs will be the same, and if powered on like that, something or somethings are going kaput.
 
Apr 26, 2022
10
0
10
Welp, looks like we've got a damaged cpu or motherboard - or both.
This gets talked about often in the power supply section of the forum: don't mix cables from other psus - there's no guarantee the pin outs will be the same, and if powered on like that, something or somethings are going kaput.

I had no clue :(. I only received one CPU cable in the Corsair and just thought they were universal cables. Pwned. Based on the noise I heard, is there any reasonable way to deduce what part is damaged?

Edit: I just looked at the pins from the EVGA and the Corsair cable and they appear to be the same on the outside but I assume there is something else that goes on inside of the cable which determines differences?
 
Last edited:

Phaaze88

Titan
Ambassador
I had no clue :(. I only received one CPU cable in the Corsair and just thought they were universal cables. Pwned. Based on the noise I heard, is there any reasonable way to deduce what part is damaged?
Although you didn't know, the board can be started up by the single EPS cable. The 2nd one is more for overclocking.

Unfortunately, there isn't a way to narrow it down based on the noise - you'll have to narrow it down yourself... and likely have to take it to a shop to help with this, as you likely don't have any spare parts to test with.

Take the gpu and EVGA EPS cable out of the board, plug the display into the motherboard so you can see if you can POST with the 12900K's iGPU.
If that fails, you'll have to go to a shop:
-swap out the motherboard, see if it POSTs.
-swap out the cpu, ditto.
Swap out ram... but, since the LEDs lit up, that means they're still getting power from the psu. It's probably between the cpu and mobo, or both are damaged.
 
Apr 21, 2022
10
1
15
Thats weird, I just replaced my PSU yesterday and left the same 8pin connector in the slot on CPU slot on the mobo, then plugged the other end into my new psu. Corsair 850 to a 1000
 
Hello All,

I recently put together a new build (poorly it seems). Below are specs.

  • Phanteks 500a DRGB w/ one exhaust fan
  • EVGA 3080 TI Hybrid AIO
  • Intel 12900K with Corsair H115 Elite AIO
  • MSI Z690 WIFI Carbon
  • Samsung 980 Pro 2TB
  • Corsair HX850 Platinum
  • GSkillz TridentZ 6000Mhz 36CL 16x2 (in slots 2 and 4)
I attempted to boot the machine and all fans/lights came on for AIOs and case fans but no input to monitor through DP or HDMI for either onboard Intel UHD or external card. I realized that I didn't plug in the CPU power from mobo to PSU. I plugged in 2x 8 pin connectors to the mobo (one was a 4x4 split) and then to the PSU. Powered on computer and heard a sound that was akin to tires squealing or something getting caught in a fan, however, I could not isolate it and powered computer off. Only the RAM lit up during this power on and down.

At this point, I am presuming the worst but don't want to proceed any further until I get input from others. Any help troubleshooting would be greatly appreciated. I am in the process of taking pictures and will post them soon. Thank you.
I'm guessing the squealing noise was something in the CPU VRM section going ape shizz with wrong polarity.
 
Last edited:

Phaaze88

Titan
Ambassador
Thats weird, I just replaced my PSU yesterday and left the same 8pin connector in the slot on CPU slot on the mobo, then plugged the other end into my new psu. Corsair 850 to a 1000
Odds were in your favor that the OEM for both units was the same, thus using the same pinouts for grnd and +12v. That's not always the case, though.
 
  • Like
Reactions: drivinfast247
Apr 26, 2022
10
0
10
Just an update. Shop isolated the primary problem as being the PSU. When utilizing their PSU, computer posted and appeared to be working normally as far as the BIOS and temperatures go. I presume there still may be damage to the mobo and CPU, but I won't know that until stress testing the machine when I get another PSU. Will update when that happens.