Roundbaby

Problem solved, and it ended up being user error. The original motherboard WAS defective, but we had slightly misconnected the front panel jumpers on the new motherboard. Still surprised that there wasn't even at least motherboard lights to show sign of life when power was switched on the PSU. Thanks for everyone's help on the matter!

Yes, we have been trying to troubleshoot it with just the AC power cable connected to see if we can get fan to spin up and see the system come alive. We don't have a PSU tester and have mainly been using the multimeter to check voltages. We have also tried: swapping out the power cable & wall outlet shorting the reset SW jumper on the motherboard checking both motherboards for damaged components or burnt traces removing RAM, GPU and storage one at a time and try to boot to see if we get any error code from the motherboard Our only lead at this point is that the PSU can't provide enough current for boot. Maybe it can provide enough for case fans to spin but nothing else. We're ordering a new PSU today and will give updates. Please send any other recommendations!

Hi, My brother has a Windows 10 Desktop PC with the following specs: MSI RTX 4060Ti Ventus 3x MSI B550 Gamer Plus Motherboard (Previous Motherboard: MSI B365M Mortar) AMD Ryzen 7 5800X (Previous CPU: Intel i7 9700KF) 32GB GSKILL Ripjaw 3200MHz Thermaltake 600W Smart Series Random Wifi Card 1TB NVME M.2 Samsung 1TB SSD He put the computer to sleep overnight with the previous components. In the morning it didn't boot and there was no response or lights from the motherboard. We immediately assumed it was an issue with the PSU, so we did the paperclip test and used my multimeter to check the voltages. All the voltages checked out and it was able to drive the case fans, so we assumed the PSU was good. The logical solution was that either the motherboard or CPU was bad. Long story short, we ended up replacing both with the new components in the above list. After going through all the work of rebuilding it, we are getting the exact same behavior -- no motherboard lights, no boot, PSU ostensibly fine. Our last ditch effort is to replace the PSU, but we wanted to get a second opinion on this. Can the PSU report "power good" and reasonable voltages on each and every pin of the 24-pin motherboard connector and be nonfunctional? Please let us know, because we've been pulling our hair out about this! Thanks, -Jacob

I am beginning to feel this issue is software related, since there are two main areas where the reset occurs: 1) give or take 3 seconds after BIOS splash 2) after "Preparing Startup Repair" when the screen says "diagnosing this PC" I can sit in the BIOS as long as I want and even access my windows disk image without error. However, after clicking "install now" when installing windows in the install image, a few moments before the product key screen would appear, the restart occurs Sometimes I get lucky and can get past "diagnosing this pc" and reach the advanced start options, and this time I decided to "Reset this PC" and completely wipe it. Maybe now I can get to windows.

Here's a breakthrough-- with no display connected, the crash frequency is greatly reduced (I can tell by seeing if the RTX logo on the GPU turns off), seemingly a crash every few minutes as opposed to every few seconds. Could it be a GPU problem? Maybe peripherals?

I'm back to BIOS splash! turns out it must have been an issue with the ram, causing the GPU to not be recognized by the mobo. With one stick in, we're back to the computer cold restarting after bios. I read something about CSM playing a role, could enabling it better my chances?

Do GPU LEDs come on if no display is connected? I would imagine so... that's the only reason I could imagine the GPU is no longer showing lights.

Here's a picture of the IHS -- The thermal paste looks exceedingly brown compared do other thermal paste, is it a feature of IC Diamond? P.S. the seating is fine, and the pins are pristine

I think I'm going to go into seating-land, will give updates

CPU power is definitely plugged in, given it's a 3900X I have all 3 4-pin connectors hooked up on both ends. Still no post.

CPU heatsink is back together, still no POST or LEDs on the gpu. Perhaps I should take a look at the pins on the CPU and reseat it? I would imagine tightening down the CPU heatsink mount would help check the seating of the CPU, but I guess not...?

I've tightened it down considerably more, and there is still some play but that might just be from the flex of the heat pipes. I originally counted CPU mounting issues out because it operated fine for 7 days with absolutely no crashing, and for it to suddenly have very immediate issues seemed impossible to be a mounting problem me... regardless, hold while I spend copious amounts of time trying to plug in the cpu fans again

I used a really fancy thermal paste my dad bought me a few years ago that's IC Diamond 7 carat compound. I was worried about tightening it down too hard, but there appears to be a little play. I am willing to tighten it down more, but how much would you say is tight enough? I don't know what the likelihood is of being strong enough to tighten to the point of cracking the IHS, but I'm very nervous when it comes to these kinds fo things

Ok, the problem has progressed just now. Now, I cannot even get to the bios splash, or at least there is no signal reaching the monitor. Also, the lights on the GPU are no longer turning on either, which was normally immediate after hitting the power button. I was really hoping I wouldn't have to check the CPU because the NH-D15 is a beast of a cooler and is impossible to reach around to plug the fan cables in, but it appears I have no other option. It should be noted that I have the PC on it's side now, just so I can more easily pick and prod at things without having to move it to the kitchen table every time I wanted to re-arrange something. P.S., I tried removing some RAM to see if it would get any better (A2 & B2 slots), but still no good. I'll update on the health of the CPU seating

PSU: EVGA G5 1000W 80+ Gold The one I had originally was 850W, and I also thought it could be a power target issue so I upped it to 1000W, no avail.