Weak CMOS Battery May Prevent Your Computer from Booting!

[Fly Guy]

For the last two years I couldn't figure out why my three year old computer wouldn't boot. It wouldn't turn on after a power outage. And even if I did properly shut down the computer the night before, it still wouldn't turn on the next morning. I would have to drain the computer by disconnecting the PSU. At first it was a few minutes, then it gradually took a whole day for the computer to drain, then only would the computer boot up. What confused me was the computer worked like a champ when the computer decided to power on.

Then just last week my computer acted even more strange than what I've described above. The computer would power up after pressing the power button but then it would immediately shut down after two seconds. I looked online and the comments were mostly, "The culprit is most likely the PSU. You need to test your computer with another PSU."

Another person with similar computer issues like me jumped through loops with the advice they gave him online, e.g. re-seat hardware, install another PSU, etc. None worked so he decided to change CMOS battery. The computer then worked like a champ again and has no problem booting. And so did this too work for me. No costly unnecessry PSU, CPU, RAM, MOBO replacement.

Anyone has any theories as to why a weak CMOS battery would prevent the computer from booting and shutting down mid way before a complete boot? It's ridiculous. You will not find this advice on the web that the CMOS battery could be the culprit because as they explain, "The purpose of the CMOS battery is to only hold date and time. A dead or weak CMOS battery will not prevent the computer from booting. You'll just lose date and time."

[Derceto]

For the record, I recently had my battery die on my ASUS Maximus V Gene. Caused the same problems as the OP. Computer would not turn. Discharged the board and PSU, replaced the battery after 10 mins, and it would turn on and work fine. Once the I shutdown the computer again after a couple of hours, it would not turn on again. Replaced the battery, worked like a charm from then on.

Surely not coincidence. Guessing the circuits are designed differently by different manufacturers of course. It may be a purposely designed feature to force the board to have a good battery in place to power on. Only way to know would be to ask the manufacturer.

In any case. I can verify the battery was the culprit in my situation as well. New battery, no problems.

[Fly Guy]

Derceto původně napsal:

For the record, I recently had my battery die on my ASUS Maximus V Gene. Caused the same problems as the OP. Computer would not turn. Discharged the board and PSU, replaced the battery after 10 mins, and it would turn on and work fine. Once the I shutdown the computer again after a couple of hours, it would not turn on again. Replaced the battery, worked like a charm from then on.

Surely not coincidence. Guessing the circuits are designed differently by different manufacturers of course. It may be a purposely designed feature to force the board to have a good battery in place to power on. Only way to know would be to ask the manufacturer.

In any case. I can verify the battery was the culprit in my situation as well. New battery, no problems.

Actually it was the PSU that was the problem. After purchasing a new Corsair AX860 a month ago, I haven't ran into that problem again. I agree with what most people say. If you run into problems like this 9 out of 10 times it's the PSU.

[_I_]

yes dead cmos battery can cause problems booting

when bios is reset, drive boot order and raid settigns, can cause os not found errors
or cpu/ram settigns can cause other errors if it defaults to the wrong settigns

[Derceto]

Genghis Khan původně napsal:

Derceto původně napsal:

For the record, I recently had my battery die on my ASUS Maximus V Gene. Caused the same problems as the OP. Computer would not turn. Discharged the board and PSU, replaced the battery after 10 mins, and it would turn on and work fine. Once the I shutdown the computer again after a couple of hours, it would not turn on again. Replaced the battery, worked like a charm from then on.

Surely not coincidence. Guessing the circuits are designed differently by different manufacturers of course. It may be a purposely designed feature to force the board to have a good battery in place to power on. Only way to know would be to ask the manufacturer.

In any case. I can verify the battery was the culprit in my situation as well. New battery, no problems.

Actually it was the PSU that was the problem. After purchasing a new Corsair AX860 a month ago, I haven't ran into that problem again. I agree with what most people say. If you run into problems like this 9 out of 10 times it's the PSU.

Good to hear you got it settled. In my case, it's certainly not the PSU though. It's in tip top shape with all the testing I did on it to verify. The new CMOS battery fixed everything. Power cycles without issue and everything is A+ again thankfully.

[oliverspalding]

genghis KHAN původně napsal:

For the last two years I couldn't figure out why my three year old computer wouldn't boot. It wouldn't turn on after a power outage. And even if I did properly shut down the computer the night before, it still wouldn't turn on the next morning. I would have to drain the computer by disconnecting the PSU. At first it was a few minutes, then it gradually took a whole day for the computer to drain, then only would the computer boot up. What confused me was the computer worked like a champ when the computer decided to power on.

Then just last week my computer acted even more strange than what I've described above. The computer would power up after pressing the power button but then it would immediately shut down after two seconds. I looked online and the comments were mostly, "The culprit is most likely the PSU. You need to test your computer with another PSU."

Another person with similar computer issues like me jumped through loops with the advice they gave him online, e.g. re-seat hardware, install another PSU, etc. None worked so he decided to change CMOS battery. The computer then worked like a champ again and has no problem booting. And so did this too work for me. No costly unnecessry PSU, CPU, RAM, MOBO replacement.

Anyone has any theories as to why a weak CMOS battery would prevent the computer from booting and shutting down mid way before a complete boot? It's ridiculous. You will not find this advice on the web that the CMOS battery could be the culprit because as they explain, "The purpose of the CMOS battery is to only hold date and time. A dead or weak CMOS battery will not prevent the computer from booting. You'll just lose date and time."

Well, I really hope you are right as I'm going through the same ordeal! I had the same problem last year and, having read the various articles, I replaced the PSU with a bigger Corsair AX750 unit. The PC has been working fine for the subsequent few months. Then last night, the PC shutdown inexplicably and refuses to boot - the power button will light, the fans begin the spin-up and a fraction of a second later it powers down again. I've disconnected from the mains to drain the PSU but that had no effect.

So, I will now go and get myself a new CMOS battery in the hope that there's a nice simple (and cheap) fix versus the alternatives!

[Bad 💀 Motha]

Just test the voltage of the CMOS battery.

[nailz]

I have to support the fact that a flat CMOS battery causes more problems than just the date time and bios values.
My PC had a wile raft of problems, failing to pass the vendor splash screen, failing to boot windows, random USB device drops, irq less or equals errors, windows freezing, games crashing, failing to shut down (the monitor would turn off, but not the PSU or HDD), power button not working, etc etc.
Since banging a fresh cr2032 in, all these problems have gone, my PC boots in record time, 20-30 seconds into win10, and shuts down just as quickly.
I think that in some cases, mobos are designed such that if the batt is completely dead, with no flow whatsoever, a circuit isn't completed, causing untold grief,
So, not to knock anyone, but to all the threads and people saying it's not the battery, it might be, and for the sake of a £.99p battery, what's the harm in checking?

[The Giving One]

nailz původně napsal:

I have to support the fact that a flat CMOS battery causes more problems than just the date time and bios values.
My PC had a wile raft of problems, failing to pass the vendor splash screen, failing to boot windows, random USB device drops, irq less or equals errors, windows freezing, games crashing, failing to shut down (the monitor would turn off, but not the PSU or HDD), power button not working, etc etc.
Since banging a fresh cr2032 in, all these problems have gone, my PC boots in record time, 20-30 seconds into win10, and shuts down just as quickly.
I think that in some cases, mobos are designed such that if the batt is completely dead, with no flow whatsoever, a circuit isn't completed, causing untold grief,
So, not to knock anyone, but to all the threads and people saying it's not the battery, it might be, and for the sake of a £.99p battery, what's the harm in checking?

That is interesting and thanks for the very informative post here ! No matter if others disagree, we appreciate your helping out in this thread !!

[RazorX]

Re: "Just test the voltage of the CMOS battery." - Testing it will give you a general idea if it's low, but to fully test it, it must be put under a load. The 2032 CMOS batteries are cheap and easy to find, so it's faster to forget testing them and just plop in a high quality Energizer or Duracell battery. In fact, before you begin ANY new computer build, you should always start by replacing the CMOS battery with a brand new one to avoid headaches down the road. You never know how long that CMOS battery was sitting on a shelf before it was installed into that new motherboard and even at that, they put in the cheapest piece of junk battery they can.

[Bad 💀 Motha]

U just test it with a voltage meter, no load is needed.
Just like with other battery. 2032 are rated for 3.0V if this falls to below 2.9; then it is dying.
Most BIOS (if it boots and the battery is working somewhat) should show the CMOS Battery 3V voltage.

If you need them cheap, look on Amazon or preferred retailer. A lot of local stores charge like $5 per battery for these kinds; don't get ripped off.

https://www.amazon.com/s/url=search-alias%3Daps&field-keywords=CR2032+battery

They can hold their charge for many years with regards to un-used/shelf-life. So buying them cheaper in bulk is not a bad idea. Especially since many folks have many PCs, this helps you out there to cover those. Plus they are often used in other devices and such; like Car Remotes

[viperwolf02]

so im having the same exact problem with my rampgae 4 extreme board. I have to pull the cmos battery and then replace. Its boots great after that and runs normal. This was a slow process at first. I would try and boot and once in a while it would not do anything. So i would kill the power to the PSU and let the lights go out. Then try again and it would boot, now it wont boot unless i pull the battery and put it back in. I have to hopefully find a battery, im in the philippines now. Finding things here are alittle more difficult. Hopefully i get it resolved before No mans Sky is ready. Ill post back wih the results, but like other i dont understand why?

My understanding of the battery must not be correct if its causing my PC to act this way. I checked the PSU and it seems good.

Its a rampage 4 extreme ASUS
32gb of Ram at 2133 Corsair

[[☥] - CJ -]

Okay so to sum things up..

Would a bad or dead cmos battery stop a PC from turning on?

I'm helping a family friend fix her old Dell Vista bound PC and it wont power on.. The board is getting power but hitting the power button does nothing..

I'm thinking that there may be an issue with the power button, but id rather not transfer the PC to another case to find out and im planning on selling her my old PC instead so i can get rid of it and so she wont have to spend more than she'd like on a new PC.

So im thinking its either the power button or the Powersupply, but i know the board is getting power.

As this thread fit my issue it helped me avoid creating a new thread.

[_I_]

ahci might cause that if the cmos battery is low and it resets without telling the os that bios settings were changed
windows wont boot with non approved bios changes

[[☥] - CJ -]

kk thanks

[viperwolf02]

yeah im confused, Ive read so many issues revolving around this with RIVE boards.
Should the Cmos show 3.3v on a meter? i tried another battery from my car remote, its 3.05 and the one that came out of the pc is around the same.

Its still doing the same things, except all of a sudden i went from 32gb of ram to 16. Saw 2 dimms showing abnormal D1 and D2, pulled the ram out but in same order. I put two different ones in the 2 bad dimm slots. they checked ok after that. So i added two more, they checked out. added two more, then B1 and B2 dimms where abnormal. keep in mind the two ram sticks that where in D1 and D2 i left out. so these wher working sticks. So i pulled B1 and B2 and put them in other slots then put the two orginal bad sticks in there place. Now all 32gb show running ok at 2133. im confused on that one.

Im taking it to a tech guy tomorrow that will sit down and help me trouble shoot. I have an XFX 1250 pro PSU. I wonder if something is just not supplying right. once the Pc is powered up i can run the crap out of it. Overclocking everything like normal. Its just getting it to start.

And for those that ask, at one time i was running quad 7990s and 64gb of ram. reason for the PSU. Any ideas?

BTW this PC build has served well for several years with just chaning GPUs out.