[Unable to access BIOS on boot]

My machine has lost the ability to let me access the BIOS.
When I start up there is no boot up sequence screen shown as it used to neither is the Gigabyte logo screen shown displaying the key presses to enable four different actions prior to full start up.

I have tried pressing the requisite key to access the BIOS but to avail.

I can get into a Command line and the msconfig but can't see anything that would get me back to being able to access the BIOS.

Not sure the exact point in time at when this happened as I always put my machine to sleep, but I think it was before W8.1 coming to us.

 

Hi - thank you for the posting advice PeteC also your advice TonyT, which I really should have thought of myself as I have done this before with previous machines for other reasons, but as I am using the machine without any trouble except for this inconvenience, it didn't occur to me.

I will get to it this week and let you all know the result

Thanks
RLC

 

FTR, CMOS (complementary metal oxide semiconductor) is a memory device that has been around in electronics much longer than the PC.

It's primary characteristic when compared to other memory devices is that it INSTANTLY (within a single clock cycle or two) dumps its stored data when the power ( "holding voltage ") is removed from the power input pin of device.

When IBM engineers developed the first PC, they needed some place to store "user changes" to the BIOS defaults (like date and time, boot order, etc.) that would remain when the computer was turned off, but could EASILY be reset!

So IBM engineers purposely selected CMOS modules and a small battery for that task.

IF the design called for those "user changes" to the BIOS defaults to be hard to reset, they would have selected a different type device - such as a EPROM or EEPROM, not a CMOS module. And/or they would have included "storage capacitors" in the circuit to keep power on the "voltage holding pin" of the CMOS module. But they did neither!!!

My point is this. When you remove the CMOS battery (or use a reset jumper), that "holding voltage" is instantly removed from the CMOS module and any data stored within is instantly lost forever. AND because the battery is now out of circuit (or shorted - bypassed - by a jumper), even if there were capacitors in the circuit holding a charge (there aren't, but if there were capacitors) the circuit is open! No current can flow because the battery is not in place completing the circuit, or the current is being shunted directly to chassis ground by the jumper (also called "shunts ") and not to the CMOS module.

So, when you remove the CMOS battery or use the CMOS reset jumper (or button with some motherboards), you don't have to wait 30 minutes, 10 minutes or even 1 minute. 10 - 15 seconds is more than enough.

 

Yes Bill, absolutely right, I've done this just lifting the battery out and replacing straight away. Nice to know a bit of history on the MB BIOS Chip - I did this before jumpers became installed on MBs.
Incidentally, these batteries (of which I have several stored) keep their charge quite well; at least the ones I have do!!