[SOLVED] Can't locate the CMOS battery on my ASUS z690-G

Jan 8, 2022
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Hi

Each time I unplug my computer I need to press the CMOS reset switch on the back of the case. Otherwise the computer won't boot. That's why I want to replace the CMOS Battery but I can't find it on my Motherboard. I guess I'm just blind.
Here's the excact model:

Thanks for your help
(Couldn't find it in the manual either..)
 

Zerk2012

Titan
Ambassador
I was looking for that too as a couple of the high end Rampage and Crosshair boards that just came out have them wired to a similar connector glued to and buried under the armor, though it looks a little bigger.

Another model of a ASUS board the battery is on the back of the USB port and 2 pin wire.
EDIT The 2nd link shows the battery the picture is the location and wire.
And again covered up with the heatsink. https://rog.asus.com/us/motherboards/rog-strix/rog-strix-z390-i-gaming-model/

https://epicpc.com.au/PHOTOS/REVIEWS/2018/ASUS ROG STRIX Z390I/_FIN9848.jpg

View: https://i.imgur.com/WSOKWUu.jpg
 
Last edited:

Rogue Leader

It's a trap!
Moderator
There is no indication of a CMOS battery anywhere in the manual other than on the last page where there is a warning about throwing it out. I wonder if its been tossed in favor of some sort of rechargeable battery or some sort of writeable persistent memory chip that doesn't need to be powered at all times. There is a CMOS wipe button on the back of the board, I would assume the system needs to have power attached for that button to work.

Side note, this board is WAY too new for the CMOS battery to have failed anyway. Your problem likely is not the need to reset the CMOS but some sort of hardware in compatibility or bad settings in your bios for your Memory.

Give us some more details on your full system specs as well as what settings you are putting into the BIOS.
 
Jan 8, 2022
10
2
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You mean the circular thing on the bottom left? I don't have that on mine. I also checked the back of the board - no luck.

I didn't change anything on the BIOS - as it resets anyway to default settings. Which settings do you need to know?

System informations:
  • Intel Core i9-12900K
  • ASUS ROG STRIX Z690-G WiFi
  • NVIDIA GeForce RTX 3080 10GB | Gigabyte Gaming OC LHR
  • 2 x 16GB Corsair Dominator Platinum RGB DDR5-5200
  • 2TB Samsung 980 Pro
  • 1000W - be quiet! Straight Power 11 Platinum
BIOS is updated to the newest Version.
Ram seems also fine (did memtest86 a couple of times.
 

Zerk2012

Titan
Ambassador
You mean the circular thing on the bottom left? I don't have that on mine. I also checked the back of the board - no luck.

I didn't change anything on the BIOS - as it resets anyway to default settings. Which settings do you need to know?

System informations:
  • Intel Core i9-12900K
  • ASUS ROG STRIX Z690-G WiFi
  • NVIDIA GeForce RTX 3080 10GB | Gigabyte Gaming OC LHR
  • 2 x 16GB Corsair Dominator Platinum RGB DDR5-5200
  • 2TB Samsung 980 Pro
  • 1000W - be quiet! Straight Power 11 Platinum
BIOS is updated to the newest Version.
Ram seems also fine (did memtest86 a couple of times.
So your saying the BIOS resets back to default every time you start the PC.

EDIT If that is true then your memory should be running 4800 as anything over that is a OC setting.
 

Rogue Leader

It's a trap!
Moderator
You mean the circular thing on the bottom left? I don't have that on mine. I also checked the back of the board - no luck.

I didn't change anything on the BIOS - as it resets anyway to default settings. Which settings do you need to know?

System informations:
  • Intel Core i9-12900K
  • ASUS ROG STRIX Z690-G WiFi
  • NVIDIA GeForce RTX 3080 10GB | Gigabyte Gaming OC LHR
  • 2 x 16GB Corsair Dominator Platinum RGB DDR5-5200
  • 2TB Samsung 980 Pro
  • 1000W - be quiet! Straight Power 11 Platinum
BIOS is updated to the newest Version.
Ram seems also fine (did memtest86 a couple of times.
Well no my point is, when you hit the reset CMOS button to set it back to defaults, I am assuming you're going in and setting some settings before boot up. Then the system boots up fine but on reboot it won't boot. What are you putting into the BIOS on the initial boot after your reset? It's possible one of them is causing it not to boot. Often its memory settings, not that theres anything wrong with the memory but a bad setting can do that.
 

Rogue Leader

It's a trap!
Moderator
What do you mean with "unplug"? From the wall? And why do you do that?

Wonder btw if it is hidden under the wifi connectors where it seems you can unscrew that.


Also something i though about, but that should be somewhere as well.
Wait up I think I missed the unplug part. So @melthay if you DON'T unplug your system it will start up and shut down fine, and reboot, etc. Its only caused when you physically unplug it from the wall (and why are you doing that anyway?)

I mean the lack of battery presence, and the fact its screwing up when he unplugs it, tells me maybe it has no battery nor way to permanently save settings, which seems really really dumb, especially on a high end board.
 

DRagor

Illustrious
Well, even if there is no battery at all, after unplugging it, the system still should boot to BIOS asking to load optimized defaults (at least that's how it worked with older boards). While the OP claims the system in that case will not boot at all unless he resets CMOS. While it is possible such change could be made, I would say that would be even more dumb then having no battery at all.
 
Reactions: Rogue Leader
Jan 8, 2022
10
2
15
0
Well no my point is, when you hit the reset CMOS button to set it back to defaults, I am assuming you're going in and setting some settings before boot up. Then the system boots up fine but on reboot it won't boot. What are you putting into the BIOS on the initial boot after your reset? It's possible one of them is causing it not to boot. Often its memory settings, not that theres anything wrong with the memory but a bad setting can do that.
I don't change anything after it goes to the BIOS when i hit the clear CMOS Button. Date / Time also match which is weird. So the battery doesn't seem to be issue from my very basic understanding of bios and hardware in general.

EDIT If that is true then your memory should be running 4800 as anything over that is a OC setting.
Yep it is at 4800 when it resets.

Wait up I think I missed the unplug part. So @melthay if you DON'T unplug your system it will start up and shut down fine, and reboot, etc. Its only caused when you physically unplug it from the wall
Exactly, if I keep it plugged in it works.

(and why are you doing that anyway?)
Well, I have everything wired up so I can just switch my light switch and it turns every device off (ofc I wait until the computer shuts down). I changed it to keep my computer plugged in permanently and it works so thanks for the advice guys! :)

Still a bit weird imo. I never had that issue in the past with other computers. I'm a bit worried that it is a defect motherboard, but I'll monitor the situation in the next weeks.
 

Rogue Leader

It's a trap!
Moderator
Well, I have everything wired up so I can just switch my light switch and it turns every device off (ofc I wait until the computer shuts down). I changed it to keep my computer plugged in permanently and it works so thanks for the advice guys! :)

Still a bit weird imo. I never had that issue in the past with other computers. I'm a bit worried that it is a defect motherboard, but I'll monitor the situation in the next weeks.
Yeah I mean that resolves the problem but would love to know WHY there is no battery. I mean in the end you should be able to unplug your computer and plug it back in and have it boot up the first time. This would be normal behavior.

Would love to hear what ASUS tech support has to say about it.
 
Reactions: DRagor

DRagor

Illustrious
Still a bit weird imo. I never had that issue in the past with other computers.
I actually wonder how you found out that reseting CMOS fixes your no boot? Blind luck or maybe there was something in manual?
Also I agree 100% with Rogue Leader we would love to hear what Asus tech support has to say on the matter. Considering how they screwed one of their Z690 boards (was that Hero if I remember correctly) I would not be really surprised if that was not bad mobo but 'working as intended'.
 

Rogue Leader

It's a trap!
Moderator
I actually wonder how you found out that reseting CMOS fixes your no boot? Blind luck or maybe there was something in manual?
Also I agree 100% with Rogue Leader we would love to hear what Asus tech support has to say on the matter. Considering how they screwed one of their Z690 boards (was that Hero if I remember correctly) I would not be really surprised if that was not bad mobo but 'working as intended'.
Seems like something they would do on a cheap junk board not a high end board like this. But still wouldn't be shocked based on all of our investigating if that were the case.
 

Vic 40

Titan
Ambassador
Been comparing motherboards of that series and saw one difference,



the red circled litle connector which would be enough to attach a wired cmos battery to.

One for comparison,




most is the same albeit maybe just at a little different placed, that connector isn't there.
 
Last edited:

Rogue Leader

It's a trap!
Moderator
Been comparing motherboards of that series and saw one difference,



the red circled litle connector which would be enough to attach a wired cmos battery to.

One for comparison,




most is the same albeit maybe just at a little different placed, that connector isn't there.
I was looking for that too as a couple of the high end Rampage and Crosshair boards that just came out have them wired to a similar connector glued to and buried under the armor, though it looks a little bigger.
 

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