Question Computer died, no POST, replacement parts haven't resolved the problem ?

[SnoopyWWIAce]

System:
CPU: AMD Ryzen 9 5950X 16-core
Replacement CPU: AMD Ryzen 7 5800X3D 8-core
MOBO: Gigabyte B550 AORUS ELITE AX V2
GPU: rtx 3080 ti
PSU: EVGA Supernova 850 T2, 80+ Titanium 850W
RAM: G.Skill RipJaws V Series 64GB (4 x 32GB) 288-Pin SDRAM DDR4 3600

Context:
System is roughly 2 years old and died recently in the middle of use, power button did nothing, no fans or LEDs and the power button didn't light up. I initially thought the PSU was the issue, I purchased a replacement 850W power supply and a tester. Ironically, the tester indicates the new PSU is DOA, but the old PSU checks out fine. Neither PSU could get the computer to power on. I don't recall if the power button and fans came on at this point, but the PC didn't post even if it did. Next I replaced the motherboard and then the CPU, both had the same result: The power button lit up, fans spun up and continued to run, and LEDs on the GPU and mobo lit up. CPU cooling fan was running as well, but still no post and nothing on the monitors when I hooked them up.

I've reviewed https://forums.tomshardware.com/thr...deo-output-troubleshooting-checklist.1285536/ and I've verified the power cords are plugged in (including the CPU, and replaced the CPU power cord), tried booting with only 1 stick of RAM with the same result (I've tried with different sticks and installation slots), confirmed that the CPU is oriented correctly with no bent pins. I've reset the BIOS several times throughout the process.

Question:
Which components could cause a failure before the post test? With the PSU testing ok and a new motherboard and CPU, I'm unsure to to go about isolating the failure. In the past I've always relied on the post test to narrow down the issue, without it and with the replaced parts not resolving I'm at a loss.

 

[CountMike]

System:
CPU: AMD Ryzen 9 5950X 16-core
Replacement CPU: AMD Ryzen 7 5800X3D 8-core
MOBO: Gigabyte B550 AORUS ELITE AX V2
GPU: rtx 3080 ti
PSU: EVGA Supernova 850 T2, 80+ Titanium 850W
RAM: G.Skill RipJaws V Series 64GB (4 x 32GB) 288-Pin SDRAM DDR4 3600

Context:
System is roughly 2 years old and died recently in the middle of use, power button did nothing, no fans or LEDs and the power button didn't light up. I initially thought the PSU was the issue, I purchased a replacement 850W power supply and a tester. Ironically, the tester indicates the new PSU is DOA, but the old PSU checks out fine. Neither PSU could get the computer to power on. I don't recall if the power button and fans came on at this point, but the PC didn't post even if it did. Next I replaced the motherboard and then the CPU, both had the same result: The power button lit up, fans spun up and continued to run, and LEDs on the GPU and mobo lit up. CPU cooling fan was running as well, but still no post and nothing on the monitors when I hooked them up.

I've reviewed https://forums.tomshardware.com/thr...deo-output-troubleshooting-checklist.1285536/ and I've verified the power cords are plugged in (including the CPU, and replaced the CPU power cord), tried booting with only 1 stick of RAM with the same result (I've tried with different sticks and installation slots), confirmed that the CPU is oriented correctly with no bent pins. I've reset the BIOS several times throughout the process.

Question:
Which components could cause a failure before the post test? With the PSU testing ok and a new motherboard and CPU, I'm unsure to to go about isolating the failure. In the past I've always relied on the post test to narrow down the issue, without it and with the replaced parts not resolving I'm at a loss.

Practically any major component could stop whole PC not to work.

 

[SnoopyWWIAce]

Practically any major component could stop whole PC not to work.

Thanks for the response. That makes sense to me, but does that stay true when talking about the post tests running? Not getting any post code to help narrow down the failure is what's causing me issues, and I was under the impression that only certain hardware could fail prior to the post test. For example, I've had problems with a PC GPU before and have been able to pull it clean out of the PC, the computer would still run the post tests.

 

[Zerk2012]

Thanks for the response. That makes sense to me, but does that stay true when talking about the post tests running? Not getting any post code to help narrow down the failure is what's causing me issues, and I was under the impression that only certain hardware could fail prior to the post test. For example, I've had problems with a PC GPU before and have been able to pull it clean out of the PC, the computer would still run the post tests.

Remove the video card and your drives.
Use the motherboard graphics from the CPU and see if you can boot into BIOS.

 

[SnoopyWWIAce]

Remove the video card and your drives.
Use the motherboard graphics from the CPU and see if you can boot into BIOS.

Thanks for the input, I'd kept the drives plugged in until now. I tried what you suggested, unfortunately that hasn't resolved the issue. The behavior is the same, fans spin up and LEDs turn on, but still doesn't hit the post tests. I was using a single stick of RAM, I tried with a couple times with different sticks. Seems like either the new CPU or mobo are DOA or all the RAM and/or a cord is dead.

 

[SnoopyWWIAce]

Issues like yours are frustrating, where you've replaced practically all the major components and the same problem keeps occuring.

But here's the ultimate backstop, and the final solution: You know that the problem would be solved with a completely new setup. I find keeping this in mind helps to relieve anxiety, and clear my mind to stay on track on what is essentially just a problem solving process that can always be solved with enough new hardware.

Regarding a new setup, you're already more than halfway there. The GPU is next obvious candidate for swap (I always keep an old one around for this purpose). But before that, expand your thinking from the likely suspects to the unlikely, eg the power cord, the power pad it's plugged into, the AC outlet, the video cable, etc etc. Some of these sound ludicrous, but you've reached this point.

Note: From your mentioned troubleshooting, I'm assuming you've done the basic steps like minimizing your HW config, by running it on open bench with only essential components and removing the rest. And taking care of ESD precautions.

>Which components could cause a failure before the post test?

RAM, CPU, MB, PSU, GPU.

Thank you, looking into a new setup is something I should probably start looking at. With the PSU testing ok, the CPU and MOBO being new, there aren't a lot of options to consider at this point. I'll try switching some of the power cords and getting new RAM. I'm a little concerned that some of the new components may have arrived dead, but I guess I'll see what happens next. Worst case I can see about returning the components and rebuilding from scratch.