No post. How to know what is wrong with pre-built PC if there are no error codes

[RageTester]

Has anyone had PC looking like it's all good except not getting video output?

Didn't get any good suggestions on my previous topic:

I have checked the cables, 8-pin, 24-pin all looking good. CPU fans and case fans are spinning. RAM re-seated. I am contacting Sedatech support now...

Keyboard lights up, but can't tell if I am entering BIOS without video signal...

Have not tried DISPLAY port instead of HDMI.

Have not done BIOS flash.

Have not removed SSD.

Have not removed CPU.

 

[kitnoman]

Have you reseat the GPU? Since the issue is output. I would start from there. What I would do first is to reseat the GPU. Then use the other hdmi port and use displayport. If it still does not show any display, I would remove the gpu and test igpu first. You can also flash CMOS and just use one stick of ram while troubleshooting.

[RageTester]

8 minutes ago, kitnoman said:

Have you reseat the GPU? Since the issue is output. I would start from there. What I would do first is to reseat the GPU. Then use the other hdmi port and use displayport. If it still does not show any display, I would remove the gpu and test igpu first. You can also flash CMOS and just use one stick of ram while troubleshooting.

I have no GPU, only iGPU. Only 1 HDMI port, will go buy displayport cable after work...

Maybe I am stupid and red LED for 1 second counts as error. I am attaching  a video of what happens right after I use power button.

 

[Skiiwee29]

<-- thread locked -->

 

Have patience. Just because you didn't get answers right away or satisfactory answers doesn't mean you can post a new thread. You can bump your existing thread once every 24hrs until resolution is achieved.