Can't access the BIOS

[cedricfr]

Hi,

My self made ~3 y.o. computer with Asus Z97-A motherboard (latest BIOS version 2801) and Intel Core i5 4690K wouldn't start and greeted me with a
CPU FAN Error

So I removed the Liquid cooling and replaced it with a brand new air cooler (Arctic Freezer 33)

But I am still greeted with a
CPU FAN Error
Press F1 to enter BIOS

So what I want to do is go to the BIOS and deactivate CPU FAN test since the Freezer 33 only starts if the processor is hot enough.

Unfortunately I can't.

Pressing the F1 key results in a black screen, and apparently the keyboard does not work anymore - at least caps lock does not light up anymore.

I also tried pressing delete at start to no avail

Before you ask, yes the Arctic FAN is correctly inserted into CPU FAN.

I'm at a loss as to what I can do: no access to the BIOS means I won't be able to reflash it.

Any ideas ?

Note: This PC has worked for years

Updates: also tried
------------
- F2 & Delete
- Clear RTC RAM jupers
- Remove CMOS battery > 2 min
- Change Battery for a new one
- Download latest BIOS, save on USB Key & plug
- Put other fan on CPU_FAN and Arctic on CPU_OPT
- Remove Graphic card
- Remove all Cards

 

[The Paladin]

when Asus boots up, press F2 or DEL at the logo ...

 

[cedricfr]

Already tried, does not work.

Also tried: removing the CMOS battery for > 1 min & replacing with a brand new battery.

 

[The Paladin]

Well you could do a reset bios and force it manually on the motherboard. Asus usually has a jumper where you jump pins, starts it turn it off, un-jump pins reboot system if not you can always pop out your motherboard battery for 2 mins and put it back in.

 

[cedricfr]

What I also tried: place another fan in CPU_FAN and place true CPU FAN in CPU_OPT

Sometimes, it boots in Windows.
So I wanted to download the BIOS again and try to flash it again, but the computer stops after a while, from cpu overheating probably.

Also strangely, when I was in windows 10 and had it directly rebooting to BIOS, it rebooted and I just had a black screen as before.

 

[The Paladin]

your problem is starting to sound s like a motherboard fan header controller issue

 

[cedricfr]

OK,
After many, many manipulations, I succeeded. Here is what I did, in case someone get the same issue.

Issue: Can't enter the BIOS of an Asus Z97-A motherboard.
Spamming Del or F2 does nothing
Pressing F1 when asked to does nothing, brings to an empty black screen

Solution:
- If your keyboard is USB, connect it to the front on an USB2 port (black ones, not blue ones)
- Start your computer and immediately spam F8
- When you get a message 'Enter the bios to update parameters' or something similar, press F1
- Wait a few seconds
- A boot menu will appear. Select Windows boot manager
(Note that there is an option Enter Setup in the boot menu. It did not work for me and brought me back to the dreaded black screen)
- In Windows, go to the Asus page and download the latest bios for the motherboard, even if it is the one that is already used).
- Unzip the archive. It should be a filename such as Z97-A-2801.CAP, 2801 being the version, which may be different for you
- Start AI Suite 3
-Press on the left bar of AI Suite, Select EZ Update
- click on '...' and select the unzipped file you donwloaded. Flash it
- The computer will restart
- Spam Del or F2
- You should finally be in BIOS

IF this doesn't work, repeat but first reset CMOS:
- Shutdown computer
- Remove CR2032 battery for 2 minutes
- Replace
- Start computer

-Or (see manual page 1-23)
-Shut down computer
- switch CLRTC jumpers from 1+2 to 2+3
- Start computer
- Wait 15 seconds
- Shutdown computer
- switch CLRTC jumpers back to 1+2

TLDR: The BIOS or its configuration was somehow corrupt.
In theory, it could be that I purchased a new cooler for nothing, and that my old watercooler did in fact work.
I'm too tired to try now, e.g. unmount new cooler, purchase thermal paste, reassemble watercooler, mount it. Maybe later.