Asus Q-Code Error 77 with Red light

[sava2030]

Hi, i have an Asus Z790-E Wifi II 

It started when my PC went into standby mode. I restarted the PC, and then suddenly this Q code 77 appeared. I looked it up in the manual, but I don’t know what this code means. Not only do I have this problem, but I also keep seeing these black cubes in the Google Chrome web browser, and I can't explain where they come from. Maybe it’s related. I ran my PC without XMP and encountered the same problem. I have also tried resetting Windows. I hope it’s not related. Otherwise, my RAM usually runs at 7200MHz. I tested it with two different CPUs, 14900k and 13600kf. The error with the cube occurred with both. Could someone explain to me what the Q code 77 means exactly? I would be grateful.

[Jiaszzz_ROG]

Hello, @sava2030 

Could you please clarify if this issue occurred after the PC was first built or after using it for some time and occurred following any recent changes, such as a BIOS update or component replacement?
May I ask if the Q-Code and Q-Led indicators show up when boot failure occurs?
According to the Q-Code table in the ROG STRIX Z790-E GAMING WIFI II manual, Q-Code 77 indicates "PCH DXE Initialization (PCH module specific)" during boot issues, with the red Q-LED indicating CPU abnormalities. 
We advise double-checking the CPU installation and any bent pins.
Regarding the black box, does it only appear when running Chrome or in any display output scenario?
For the black box issue, consult the MB manual to ensure proper connections of the GPU, monitor, and if necessary, try cross-testing with iGPU or HDMI/DP cables.

Thank you.