Question Pc repeatedly turns on and off after changing BIOS settings

[deynoy]

I was changing settings in my BIOS (I believe it was changing something from Legacy to UEFI, trying to change it to Secure Boot and enabling some Intel Platform something stuff), restarted my computer, and now I have no display and my PC is turning on and off repeatedly. I unplugged the computer, took out the CMOS battery for 10 minutes, plugged it back in and still same result. Used screwdriver to connect 2 CLR_CMOS pins, plugged the Power On plug (thats going from i believe switch button) onto these 2 pins and held switch button for like 30 seconds. After putting back the Power On plug back into its place i tried booting my pc up again. It went into the cycle again however at the first time after starting it i heard few beep sounds (at the rate of around 1 beep per sec). I also tried taking off my RAM, putting it back in etc.and still nothing. Im pretty sure that its not PSU's fault because everything seems to get power. What May be causing the problem and how can I solve it?

 

[Lutfij]

Welcome to the forums, newcomer!

If you installed your OS under CSM, you will need to reinstall it when under UEFI. If you want to clear the CMOS, you should disconnect from the wall and display, then remove the CMOS battery, then press the power button for 30 seconds. Replace the battery after 30mins then try and power the system.

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.

 

[deynoy]

Right now im in the middle of waiting the 30 minutes to get any electric charge out. Ill write after plugging it in and checking if it works.
My pc specs are:
Cpu: i5-7400
CPU cooler: stock one
Mobo: GA-B250M-DS3H
Ram: 1x samsung 8gb 2rx8 pc4-2400t
Hdd: 2 TOSHIBA 500gb i dont know the exact model
Gpu: RX 480 8gb Gigabyte
PSU: silentum pc VERO L1 500W
Chasis: i dont know the exact model and I cant find its name anywhere. Its silentum PC tho
OS: Windows 10 Enterprise
Monitor: Samsung S22E390H
Everything was new and was bought around 6 years ago.

 

[deynoy]

Welcome to the forums, newcomer!

If you installed your OS under CSM, you will need to reinstall it when under UEFI. If you want to clear the CMOS, you should disconnect from the wall and display, then remove the CMOS battery, then press the power button for 30 seconds. Replace the battery after 30mins then try and power the system.

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.

Still same thing, turns on and off repeatedly.

 

[Unolocogringo]

As stated above, if you changed bios from CSM( legacy mode) to UEFI for Secure boot and TPM, you need to reinstall windows in UEFI mode.
They are not compatible with each other.
So go back to CSM (legacy boot) or reinstall ( complete wipe and UEFI boot) windows.

 

[deynoy]

As stated above, if you changed bios from CSM( legacy mode) to UEFI for Secure boot and TPM, you need to reinstall windows in UEFI mode.
They are not compatible with each other.
So go back to CSM (legacy boot) or reinstall ( complete wipe and UEFI boot) windows.

How do I do that when I cant even load up to the BIOS. Pc turns off after like 3 sec

 

[Unolocogringo]

You need a bootable USB with either windows 10/11 on it.

First disconnect power to power supply.
Open case and remove bios battery.
Press power button several times to drain capacitors.
Find and jumper Clear CMOS, Bios reset jumper on motherboard for 10-30 seconds.
replace battery,remove jumper if installed,connect to power and boot.
Spam (DELETE) key repeatedly on power on.
This should boot to bios instead of fast boot straight to windows boot.

To get back to original windows set boot to CSM/Legacy mode.
Restart and it should now boot your old windows install.

If you need UEFI,TPM,Secure Boot etc you need to save your files on a backup after booting to windows.
After backing up files reboot into BIOS( gotta spam DELETE to get there.) with USB with windows installer inserted.
Change from CSM/legacy to UEFI, Secure boot,fast boot TPM enabled etc....
Now go to boot menu and set the USB as first boot device.
Save and exit.
Computer should reboot and boot from USB installer.
Delete all old partitions from drive/drive partition you wish to install windows on and click next.
Windows will create needed partitions and format them,then install a new copy of windows.
Now update motherboard,video,sound drivers etc.... from the Gigabyte website for your motherboard.
Reinstall games ,apps,etc from your backup.

 

[deynoy]

You need a bootable USB with either windows 10/11 on it.

First disconnect power to power supply.
Open case and remove bios battery.
Press power button several times to drain capacitors.
Find and jumper Clear CMOS, Bios reset jumper on motherboard for 10-30 seconds.
replace battery,remove jumper if installed,connect to power and boot.
Spam (DELETE) key repeatedly on power on.
This should boot to bios instead of fast boot straight to windows boot.

To get back to original windows set boot to CSM/Legacy mode.
Restart and it should now boot your old windows install.

If you need UEFI,TPM,Secure Boot etc you need to save your files on a backup after booting to windows.
After backing up files reboot into BIOS( gotta spam DELETE to get there.) with USB with windows installer inserted.
Change from CSM/legacy to UEFI, Secure boot,fast boot TPM enabled etc....
Now go to boot menu and set the USB as first boot device.
Save and exit.
Computer should reboot and boot from USB installer.
Delete all old partitions from drive/drive partition you wish to install windows on and click next.
Windows will create needed partitions and format them,then install a new copy of windows.
Now update motherboard,video,sound drivers etc.... from the Gigabyte website for your motherboard.
Reinstall games ,apps,etc from your backup.

The problem is that I cant get to BIOS in any way. I can spam DEL but it still will restart before the BIOS even pops up.

 

[Unolocogringo]

Did you do the hard bios reset as I described above?
Take out battery... Whole ordeal?
This should make the bios forget the changes you made and reset everything to default bios settings. Puts everything back to auto mode.
Then first boot after the BIOS checks every installed device needed to boot and boots in sort of "safe mode" into the bios. And makes a small File of attached devices and their address, capabilities etc.." Fast boot" .

 

[deynoy]

Did you do the hard bios reset as I described above?
Take out battery... Whole ordeal?
This should make the bios forget the changes you made and reset everything to default bios settings. Puts everything back to auto mode.
Then first boot after the BIOS checks every installed device needed to boot and boots in sort of "safe mode" into the bios. And makes a small File of attached devices and their address, capabilities etc.." Fast boot" .

I did what you said, took out the mobo battery for 30 minutes, held power button for 30 seconds and clicked power button for 30 seconds because i didnt really know which one you meant. It didnt work. Tried making 2 CLR_CMOS pins make contact with eachother by putting screwdriver between them and then holding the power button. It didnt work. Tried to put the Power On 2 pin plug onto the CLR_CMOS pins and clicking power button. It didnt work. Im running out of ideas