Question BIOS has become inaccessible in my dektop tower PC

[Sebastian42]

POST instructions say 'Press DEL key to access settings', and that used to work, but no longer. I have left the CMOS battery out of the motherboard all night, and although the clock was wrong in the morning, the calendar was not. I have since shorted the terminals of the CMOS battery holder, with the same unsatisfactory result. Are there any foolproof (or almost) ways of getting to BIOS settings ?

 

[zir_blazer]

Not enough data. What Motherboard are we talking about? USB Keyboard?

 

[Sebastian42]

I deliberately decided to 'limit' my information until such time as RELEVANT questions were asked.
Mobo is Gigabyte Technology Co., Ltd. - GA X58A-UD5; keyboard connects by USB.
When I had access to BIOS, I was using a P/S2 connected keyboard; I switched to a USB connected keyboard to prevent unwanted enabling of OVERTYPE mode.

 

[maluckey1]

You can enter the "BIOS" from a Windows 10 shutdown. A google search will give you the detes.

 

[VirtualLarry]

Mobo is Gigabyte Technology Co., Ltd. - GA X58A-UD5; keyboard connects by USB.
When I had access to BIOS, I was using a P/S2 connected keyboard; I switched to a USB connected keyboard to prevent unwanted enabling of OVERTYPE mode.

Try different USB ports, some are often more "primary" than others. (USB2.0 ports for mouse/keyboard if you can).

 

[Micrornd]

Have you tried a different keyboard?
Does your keyboard have any lights on it (numlock, etc.) that would indicate it is getting power (active) at the time you need to press "delete".
Usually USB 2 ports are always active at boot, but not all USB 3.x are.

 

[CentroX]

I recently helped someone else with the same problem on another forum.

Here is the fix:

Unplug your DP cable and insert a HDMI cable to your GPU.

 

[maluckey1]

I recently helped someone else with the same problem on another forum.

Here is the fix:

Unplug your DP cable and insert a HDMI cable to your GPU.

The above method also works if you are using resize bar and somehow (power surge, swapping monitor sources etc) the computer thinks that CSM is needed, and tries to "help" you out.

 

[Sebastian42]

The earliest question about my type of keyboard gave me the hint I needed. I rebooted with a P/S2 keyboard connected, and gained access to BIOS SetUp.
I'm interested in the idea that a different USB port could also be a solution. In my case awkward to test, but worth keeping in mind. Thank you so much !

 

[solidsnake1298]

It varies between CPUs, chipsets, and individual boards, but some USB ports come off of the CPU and some from the chipset or even an additional discrete USB controller that is then tied into to the chipset. Depending on how the motherboard BIOS starts everything up, its possible that the USB ports connected to the chipset or discrete USB controller start up last and your inputs aren't registered before it finishes posting.

Below is an example of the varying sources of USB connectivity.

 

[Sebastian42]

To me your diagram shows different connectivity sources for USB ports, but tells me nothing about their relative readiness.

It turns out that my keyboard is not even connected to a native PC port, but to a PCI card. I will of course try to correct that.

 

[solidsnake1298]

That is kind of the point of my diagram. How, and in what order, a motherboard boots up its various hardware is not published. You would need to speak with a BIOS engineer from ASUS, or MSI, or something.

But your keyboard not being plugged into a motherboard or CPU sourced USB port probably isn't helping things either. I'm assuming you have the PCI card because you ran out of ports on your motherboard.

 

[VirtualLarry]

It turns out that my keyboard is not even connected to a native PC port, but to a PCI card. I will of course try to correct that.

That could well have something to do with it, yes.

 

[Sebastian42]

I have now tested the same USB connected keyboard slotted into a native USB port, and BIOS is accessible. Yes I fitted a PCI card because I did run out of USB ports, but luckily swapping the keyboard to a native port was a very do-able and simple.