A few weeks ago I noticed that after powering off my PC and unplugging from the mains whilst I did some maintenance, after plugging everything back in and booting my PC I got a CMOS error....not a problem I will just replace the battery (I thought) but I can't see it!  After a bit of searching I read its underneath the plastic shroud around the Northbridge.   Today whilst moving my system to a new case, I thought this would be an ideal time to finally replacing my battery.  I have a custom loop installed so it really was the best time to do it.  After removing the motherboard, I took off the left side of the shroud where my nVME drives are, but couldn't see it.  I turned it over and seen 4 screws underneath the northbridge, I kind got scared thinking it might be holding the Fan/Heatsink directly on the northbridge so I didn't try and disassemble any further :(
 
Is it really underneath there?  Why would EVGA do this?  Not really a massive deal, I rarely unplug from the mains, but would of liked to have changed it today...oh well :(
 
Would also be nice if there was some kind of documentation about changing the CMOS Battery in the manual....

ah ha!  Thank you for the image Sajin!  Do I have to remove the heatsink and fan to get access to the battery?

Ok thanks a lot man, next time I have the motherboard out I will take a closer look, are the shroud screws all topside?  I could only see the 3 to remove the nVME covers :s  

Brill thanks again! :)

I think that a CMOS "Checksum Error" may be normal for that board when booting up after all power has been removed, not real sure..Then you just "Press F1 to Skip" and carry on.

As long as the VBAT (CMOS Battery Voltage) is no lower than 3.1v it should be OK, but I guess you're fixin' to find out..You may be able to see that voltage in the Advanced section of the BIOS where the voltages are shown, or use something like HWiNFO where it's called "BAT_3V".

See: My computer is showing a checksum error, what is this error related to? in the EVGA FAQs, and, "First Boot" in the Motherboard Manual on page 57.

Anyways, make sure the BIOS is up-to-date with Version 1.23, the latest as of now.

If it keeps your settings (that's the purpose of the CMOS battery) and only coughs up the checksum error when all power is off and is OK after pressing F1, then it's most likely normal and does that only when all power is off.
 
You can try it again to see if you can duplicate it.
 
You can Call or Email EVGA to be sure, or an EVGA Tech might chime in here and comment on it..I'm almost certain it's normal though, but maybe not.

Well I have had this mobo for a little over a year or so, and to only notice it a few weeks/months ago is a bit strange seeing as I am always tinkering...but saying that, flushed and changed my liquid last night whilst switching case so I should be good for another 12months :D
 
Thanks for all the replies, I can live with this feature :)

ironage

bob16314
I think that a CMOS "Checksum Error" may be normal for that board when booting up after all power has been removed, not real sure..Then you just "Press F1 to Skip" and carry on.

confirmed, i have the same, power supply off means CMOS Checksum Error at next post/startup.
 
just annother EVGA X299 Dark annoyance, better get used to it.

As suspected..Thx for the feedback.

Issues started when i tried 9820X overclocking with an older Bios and 10900X with per Core VC.
 
My MSI X299 SLI Plus did provide stable operation as well almost three years ago without CMOS Checksum Error after power loss.
 
For less than half of the money.
 
Do not want to b!tch about it, but there is plenty of room left for optimizations.

ironage

bob16314
I think that a CMOS "Checksum Error" may be normal for that board when booting up after all power has been removed, not real sure..Then you just "Press F1 to Skip" and carry on.

confirmed, i have the same, power supply off means CMOS Checksum Error at next post/startup.
 
just annother EVGA X299 Dark annoyance, better get used to it.

I don't experience that. I turn off the power supply, remove the power cable from it, do work on my system and when I reconnect and power on I don't get CMOS checksum error on start. Preserving CMOS while power is removed is the whole point behind having the CMOS battery, isn't it?