[SOLVED] BAFFLING system no display and errors after replacing (almost) all components

bostonkris34

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Mar 9, 2017
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Hi everyone - I'm stumped and would love some help! A couple weeks ago I flashed my bios on a z270 build to attempt to enable TPM 2.0. It went fine, I restarted, no problem. Changed a few settings in Bios and restarted a second time - and everything went kaput. Wouldn't post. The yellow boot and white VGA Q-LEDs remained lit. I assumed it was motherboard related. And because my i7700k doesn't fit on more modern boards, I had to buy a new CPU too.

So I went out and bought an Asus x570 e gaming, which arrived DOA. Switched it for an Asus B550 and a Ryzen 5900x. Also got new Corsair DDR4 3600.

Kept my EVGA 850W PSU, my Asus 1080ti GPU, and my Samsung SSD. Everything else is new. AND I HAVE THE SAME ISSUE. Computer fires up but no display. Have connected both to GPU and on-board video. Using HDMI and DP cables each. So I probably didn't need to go out and spend all this money and time to replace my MOBO and CPU... but even so, I don't have a working PC.

The yellow boot and white VGAs are still lit. I'm not even using the GPU, and I can't imagine the SSD would cause this (could it?)

Which leaves me with PSU, but that seems to be working ok... I guess maybe I wouldn't know... or why it would have failed from a bios flas. I am baffled! Before I go out and buy yet another new part, do you think this sounds like a PSU issue?

Thank you!
 
Solution
Disconnect all your drives, and see if it posts, to rule them out. You do not have onboard video, with a 5900x, just as an FYI. Also your B550 board may need a bios update, to work with the 5900x.

bostonkris34

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Mar 9, 2017
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Well, you solved it - I didn't realize this mobo didn't have an on-board GPU. So, I went back to using my 1080ti in the new build... but switched to the HDMI instead of the DP (which i thought i had done before, but i guess not)... and now it works fine (so far).

I'm thinking this means i just built a nearly brand new PC for no reason when my old setup was doing just fine. And I hope it is a cable issue vs. the DP port on my GPU failing - i'll test that later.

Crazy that the DP cable (or GPU port) would fail the exact moment I restarted after flashing bios on my old machine. I don't get it. Hopefully this isn't a fluke and the new PC continues to be ok - I have to work now but will play with it again tonight.

Thank you again - any idea why the cable or port would have failed when it did??
 

bostonkris34

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Mar 9, 2017
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Thank you for the replies! Sadly I spoke too soon - not solved yet.

Using HDMI only (I changed DP cables with no luck), I am able to get into BIOS - but am unable to get into Windows. Just one issue after another.

PSU is EVGA SuperNOVA P2 850W. It is about 5 years old.

I guess I will try doing a bootable USB windows repair tool and see if that helps.
 

bostonkris34

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Mar 9, 2017
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Wow - ok. Got it to boot to Windows by changing from DP to HDMI as mentioned (no idea why, and I need my DP ports to work so... we'll see), updating the BIOS as suggested, AND what finally worked was enabling CMS for booting from legacy and UEFI devices.

Thank you for the help! I don't understand it, but I guess it is solved? And probably, my z270 with i7700k that I thought were bricked are likely ok to repurpose. Thanks again