Question At Standstill With Dead Computer - Please Help

[lendit]

I apologize in advance for the extremely long post, but I'm at my wits end. I have no idea what's happening.

I'll just list my specs and start from the beginning:

• Case: NZXT H1 V1
• Mobo: Asus ROG Strix X570-I Gaming
• RAM: G.Skill 32 GB 3600 MHz
• CPU: Ryzen 7 5800x3D
• GPU: EVGA FTW3 RTX 3090
• PSU: Silverstone SX1000

This past Sunday, I purchased a Noctua NH-L12S (the pump on the included AIO in the H1 was starting to fail) and the G.Skill ram listed above, upgrading from 16 GB of 3200 MHz. I installed those two items without hiccup. The system ran fine for about 20 or so hours, including under load, until yesterday when it shut off out of nowhere. I had two browser tabs open, and I had left the room for about five minutes. When I came back, the system was completely off, and there was no power whatsoever. No fans would spin up, no signs of life at all. Completely dead.

I'll now go into the troubleshooting steps I've taken in an effort to diagnose the issue.

I first disassembled the system and checked all of my connections, none of which seemed out of place. I attempted to reset the CMOS using the pins on the board. After trying further to reset the system, I assumed the PSU had failed.

Assuming the PSU was the culprit, I decided to test the PSU by itself by inserting only the 24-pin ATX connector into the PSU unit and shorting the 4th and 5th pins on the top row to see if the fan would spin up or if the unit would give any indication it was working. It did not, so I deemed that the issue was a faulty power supply.

Today I went and purchased a brand new Corsair SF850 power supply. I reassembled my system, and still no power whatsoever.

I began removing parts, one by one, to see if the issue would resolve if a certain part was removed. I took this all the way down until it was just the motherboard, CPU, CPU Cooler, one stick of RAM in the appropriate slot, and the CPU and ATX power cables connected to the PSU. No storage connected whatsoever. Shorted the Power + and - pins to boot. Still nothing.

I then tested the Corsair power supply in the same fashion as the Silverstone unit; short pins 4 and 5, and the fan spun up on this unit, so the Corsair PSU is working properly.

I now assume that my motherboard is dead. I go back to Microcenter and purchase a Gigabyte B550-I Aorus Pro AX.

I start barebones this time. I install the CPU, CPU Cooler, one stick of RAM, and the power connectors. This time, short the power pins, and the PSU enters a boot loop of sorts. After removing my screwdriver from the pins, the PSU will click, the fan will spin for a second or two, and then the unit will shut down. This repeats until I shut the PSU off by the switch on the unit.

I tested both setups with one stick of my old RAM as well (16 GB 3200 MHz) and was met with the same outcome.

I even moved this little test setup I had to a different outlet in my house, on a different breaker, to see if maybe the outlet was the issue. Still nothing.

I have absolutely no idea what's going on. I pondered if my CPU was the culprit, but the boards would at least receive power and attempt to boot if that was the case, and neither do from my observation.

I really have no clue what to try next. I'm incredibly frustrated. If anyone has even the slightest clue what's going on, please leave a comment. I need this computer back up and running because I have critical files for school on the storage.

Thank you if you've read this far!

 

[Lutfij]

Case: NZXT H1 V1
Did you get the replacement kit for the riser cable that made the NZXT H1 V1 a fire hazard?

View: https://youtu.be/fjUscSRLwks

^ One of a couple of videos about the issue arising from the riser.

An RTX3090 doesn't belong in that case, and you should've looked into a 1.2KW PSU for the entire build due to transient load spikes.

I start barebones this time.
Were all pats tested while breadboarded?

I install the CPU, CPU Cooler, one stick of RAM, and the power connectors. This time, short the power pins, and the PSU enters a boot loop of sorts.
Your platform doesn't have an iGPU so you're going to need a discrete GPU, one that's low powered to rule out your PSU being incapable of powering the entire system with an RTX3090.

 

[lendit]

Case: NZXT H1 V1
Did you get the replacement kit for the riser cable that made the NZXT H1 V1 a fire hazard?

View: https://youtu.be/fjUscSRLwks

^ One of a couple of videos about the issue arising from the riser.

I did not get the replacement cable. I inspected the existing riser cable for any signs of singe marks, damage, etc and found nothing.

Edit to respond to the rest of your post:

Both setups were breadboarded.

In response to your second point, I wasn't even attempting to boot into bios, I just wanted to make sure the motherboard was getting power. I had a fan hooked up to the cpu_fan pins, and it would spin maybe once every couple of seconds. I was under the assumption that the board would still power up completely even if there was no discrete gpu installed?