just shoot me...

I have driven myself beyond insanity trying to figure out why my new build does not POST or output a video signal. I'm at the point of giving up altogether and just shelving all the parts, but before I do that, I'd appreciate any feedback you may be able to give.

Current config: ASRock B550I Phantom Gaming motherboard bought new 3 weeks ago. I can't find the BIOS chip so I don't know BIOS version. I tried two CPUs - Ryzen 5 5500 (not on QVL) and Ryzen 5 3600 (on QVL all BIOS levels). Memory is G.Skill Trident Neo 3600 C16 that came today. It lights up. GPU is Gigabyte 2070 Super, proven working on another system also running the same motherboard. PSU is Corsair RMX 750 tested out with PSU tester, also used Dagger 650 watt SFX PSU also tested out. Speaker connected to onboard header, and I don't get any beep codes. I get voltage to fan headers, GPU indicator lights show power when the start button is pressed, and USB works. I tried HDMI and DP, still no signal. I also yanked an Asus 2070 out of another computer and it made no difference. I initially built with an ASRock A520 motherboard and got the same symptoms. Same with a Gigabyte A520. I bought the B550 thinking it may not be defaulted to onboard graphics output, but nothing changed. I also cleared CMOS more than once. The 3600 CPU has been proven working in another system, while the 5500 has not been in a working system yet.

I'm totally cooked. I have no options other than tearing into my HTPC and pulling the Ryzen 5600G to bypass the GPU. I've cannibalized two working computers to diagnose and would prefer not to yank parts out of a third, but this has cost so much chasing what might be the hangup that maybe I might as well.

I'm totally confounded by having three motherboards show the exact same issues - no video and no POST. I've taken working parts out of other systems and they did not address the issues. I'm cursed... I can't think of anything else I can do.

Xaltar wrote: At this point it's time to eliminate everything in common between your different test setups. If you have not done so already, test the board outside of the case with just one stick of RAM, PSU, GPU and CPU installed, nothing else, no SATA cables USB devices etc. I have seen several instances where a simple USB keyboard prevented POST, also bad SATA cables can do the same. Above all, try to stay calm while troubleshooting, being angry almost always leads to overlooking things. Good luck

I appreciate the input. I'm beyond angry at this point. Unless I get a breakthrough, I'll just shelve the parts or Craigslist the stuff.

I put in a decade doing IT problem management for a large healthcare group, and went so far as to pull out my root cause analysis tools and use them on this. I have not done the 'one stick' test, but all else has been done. No connected USB devices, known working GPU, known working PSU, known working CPU. I'm really at the end of my rope on this. Same symptoms across THREE motherboards from two manufacturers is incomprehensible, given that I have already validated function of GPU, PSU and CPU on my other working systems. All I've got left is the one stick test, and putting in an APU. If that does not cut it god doesn't want me to have another working computer in the house.

Get a load of this...

My monitor has a 'soft off' after so many minutes, and I came back to the computer without any RAM installed and turned it on for kicks. Well, some signal is getting out of the GPU because the monitor turned itself on when I turned on the conmputer, but no BIOS splash screen or any other signal after the initial blurt that woke up the monitor. I've seen this before, always with the monitor in that soft off state after a period of disuse (RAM was installed). So, something is getting to the monitor from the GPU else it would be off still. I differentiate 'off' from sleep when the monitor's own splash screen appears. That's what happens, then I get a "no signal" message. Go figure... I'm grasping at thin straws here, but I'm wondering if the BIOS is set to provide video from IGPU and not PCIE. If it locks to that and does not simply default, then move to PCIE if IGPU's not working, then that may be a possible root cause. Also, my GPUs are PCIE 3. If the BIOS sets PCIE slot for PCIE 4 and it does not autonomously downgrade to PCIE3 then that may be a cause, but I'm not yanking my RTX 3080 to find out. It was a bear to fit in the case it's in now.

I can't cannibalize my HTPC's CPU with embedded GPU because I'd have to yank the mobo to get the heatsink off. Nope, I've thrown enough good money after bad. My root cause analysis tools tell me I'm done, but they work on the premise that something used to work once, and does not now. This is a new build so I don't have a known good for the system, only individual parts. I've already built one system with the B550I Phantom motherboard and it was very straightforward and uses a GPU, the 3080. It uses the same RAM as what I bought for this failed build. I did have the 2070 super in that configuration before the 3080 went in so the slot was PCIE 3 ready. Well, time to break out the Necronomicon and find that blood sacrifice ritual for bringing back the dead. D'OH!! This system never lived to begin with so I'm truly screwed...

The motherboard may indeed be defective. Unfortunately, I've got 3 A520 motherboards (two mfg by ASRock, one by Gigabyte), all bought presumed new (unless Newegg lied to me) and they all have the same no video or POST issue. I got the B550 motherboard thinking the A520 boards may be locked on IGPU output. I threw good money after bad and popped for a Ryzen 5500G to bypass the GPU. If that does not POST for sure I've died and gone to the Hell Satan thinks is the most painful for me. If I see him, I'll chide his sloppy work - the real Hell is living forever with my ex and her friends.