The concept of secure boot is simple: to ensure that only trusted software is allowed to launch and run.
Implementing that is not simple when so many things can happen or not happen when a system boots.
Could be just a matter of buggy or corrupted software, faltering hardware, end-user configurations , some mix even - all too common.
Not to mention the pitfalls of pirated software and malware getting in....
Disabling secure boot did not stop or end the problem. All that was accomplished was to bypass protections that are now no longer protecting the system. Potentially leading to making the situation even worse. May have already done so.
There are many online explanations about secure boot. Do some searches and read a few articles and tutorials to learn more about Secure Boot. Read articles from known technical sources - including Microsoft. There may be some fix to be found - however, that depends on finding the root cause(s) of the problem.
Next, steps:
"Do-over".
Reread and review the motherboard's User Guide/Manual and pay close attention to all fine print and details.
Again: double check all connectors, cards, RAM, jumpers, and case connections to ensure that all are correct, fully and firmly in place, and undamaged. Check by sight and feel and use a flashlight to inspect everything.
Note: I listened to that PSU "noise" again. Could not really hear anything but I am wondering about the positioning of that PSU. I see only half the fan and I am not sure about the grill work that is visible. Take a couple more photographs and post accordingly via imgur (
www.imgur.com) Show fans and indicate air flow directions.
Replace the CMOS battery and reset CMOS by following the applicable motherboard procedures.
User Verbose mode to watch what happens when/while the system boots.
Simplify: Use only iGPU (if supported) and only the boot C: drive. Disconnect other drives from use. Basic network connectivity: just wired (preferably) or wireless access. No VPNs. No extra apps or utilities of any sort in Task Manager > Startup.
No clocking or voltage changes.
The objective being to restore the system to its' base configurations where the system will fully boot without errors and remain stable thereafter.
Allow a few boots and time between boots for Windows to update and correct itself as necessary. Watch for failed or problem updates.
Clear the Event Viewer logs. The purpose being to start with a "clean slate" and make errors or other problems stand out.
If the above does not prove sucessful you can do it all over again with a clean Windows install as a new starting point.
It will all take time, patience, and effort. Be methodical, make notes, observe carefully.