PC keeps switching off and CMOS reset did not work

[lodenportier]

Context
I wanted to change some BIOS settings so I could install Windows 11.
- I enabled Intel Platform Trust Technology (PTT) on my GA-B250M-DS3H motherboard BIOS settings, and it worked fine.
- I enabled Secure Boot without any issues neither.
- But then after restarting the computer, I also changed Secure Boot Mode from Custom to Standard

Problem
The last step is where things went wrong. My PC keeps switching off and on every 10 seconds. I see a black screen.

What I've tried so far:
1. I've tried to jumper cap the CLR_CMOS on the board. (Unplugging, hitting start button a few times, touch the 2 metal pins with a screwdriver for a few seconds, try to turn on again)

1. 2. I've tried removing the CR2032 battery on the motherboard for a few minutes

Are there any other ways to reset the BIOS settings? And is that actually the problem in the first place? No clue what to do here...
Thanks!

Update 1 (a few hours later):
I unplugged the PC and took the battery out again and set it aside for a few hours to drain all energy (Read this somewhere on another forum).
The PC still keeps switching off and on every 10 seconds with a black screen. But now it comes with actual motherboard sound. It beeps.
Did I make it worse? Or is this promising? (I decided to just redo all the steps one more time and set the PC aside for even longer)

Update 2 (some more hours later):
2nd attempt didn't do it. Now it's back to the original problem I.e. the motherboard now doesn't beep anymore while the pc still switches off an on and there's a black screen.

 

[Kshipper]

Just a few things....you reset the BIOS with the PSU unplugged from the wall? When you removed the CMOS battery and you placed a jumper on the 2 pins to short them out. You did remove the jumper right? It's not still on there right? When you did hear the beeps was there a pattern to them? Was it single tone or a series of short or long beeps. Those could be POST beeps indicating an issue. It wouldn't hurt to take the RAM out and then put it back in.

 

[lodenportier]

Just a few things....you reset the BIOS with the PSU unplugged from the wall? When you removed the CMOS battery and you placed a jumper on the 2 pins to short them out. You did remove the jumper right? It's not still on there right? When you did hear the beeps was there a pattern to them? Was it single tone or a series of short or long beeps. Those could be POST beeps indicating an issue. It wouldn't hurt to take the RAM out and then put it back in.

Yes, I made sure to unplug the PSU from the wall at every attempt.

I removed the CMOS battery for 5 minutes, and used a screw driver to quickly touch both pins at the same time (I couldn't find a jumper cap).

In hindsight, I only heard the beeping because I forgot to put the two RAM sticks back. They were medium long beeps and they kept on going.

I've tried to boot without RAM, with 1 RAM stick, with both, swapping them... no effect. I've also never heard the alarm sound again in any of the other 5+ attempts.

 

[Kshipper]

OK. The beeping when all the RAM removed is to be expected because the PC is telling you I don't have any RAM via that series of long beeps. This also proves that you have logic. The CPU is working to at least tell you what it sees as a problem. When a machine first comes up after a BIOS reset it could turn on and off as it tries to go through memory training to find the right settings for the RAM. This is especially true if the RAM is capable of running faster than 2133MHz (Default DDR4 speeds).

I assume that you did give the system to time to run through memory training? It would be a lot longer startup then you are used to, so you might have assumed something is wrong and switched it off before it finished.

I would disconnect as many things as you can. Remove drives, any extra cards and even USB peripherals for the initial boot. Any bad hardware can make a system do the black screen.

It's even possible to damage components if you are not practicing static safety. I have done it, and it is all part of learning. I know use a static wrist strap connected to a functioning ground when I do my work on PCs.