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."

[宮小路健次郎]

İlk olarak ☥ - CJ - tarafından gönderildi:

Keep in mind that the only time the CMOS battery gets used is when the PC is off, So if its a PC that is a few years old and its common for you to turn the PC off then its possible the cause is the CMOS battery.

just make sure you get the correct battery, CR2032

Yep, I always turn off my Pc like 5/7 times in a week whenever I sleep, so I kinda hoped that it is just a cmos problem. Sadly, as it turns out, I really have a dead board. I just bought a new cmos and still no gucci. Might as well plan to upgrade from my dead a320m mobo. Anyways, thank you all for the sharing of information.

[palokins]

Hi guys, I have the same problem right now. My PC won't boot, no lights, fans are not starting, no beep, no signs of life...

but the weird thing is,
I happened to remember 10 years ago that a friend(who was a technician) of my brother once revived a dead motherboard by placing it under the sun. Yes with sunlight! and I don't know how it happened and I'm dead serious the motherboard was fixed and booted.

Now that I'm experiencing a motherboard that doesn't boot, I followed what that technician did by placing my mobo under the sun for about 10-15minutes(watching one youtube video).

And guess what, THE PC BOOTS UP! and I thought the motherboard was revived but after shutting it down and leaving it turned off for some time it won't boot again and I have to place the motherboard(case open and mobo with direct sunlight) under the sun again to boot it up. I have to do this process over and over again just to turn on my PC T_T.

Can someone explain this to me? WTF is happening?
After reading this thread, I'm thinking it has something to do with the CMOS Battery getting some charge with the sunlight. I'm getting a new CMOS Battery tomorrow and hopefully it'll fix my problem. I'll also try to borrow my cousin's PSU as a last resort if replacing the CMOS Battery doesn't work

[GOD RAYS ON ULTRA™]

Well, considering I've fixed video cards before by placing them in the oven, I can only guess the sunlight has a similar effect; albeit not a permanent solution like the oven.

[[☥] - CJ -]

probably some bad solder joints or something, but yeah, baking is common..

[Autumn_]

İlk olarak ☥ - CJ - tarafından gönderildi:

probably some bad solder joints or something, but yeah, baking is common..

Except how could sunlight make something ~200c.... the melting point of (most) solder.

[[☥] - CJ -]

well thats true
no idea

[The Giving One]

İlk olarak Autumn_ tarafından gönderildi:

Except how could sunlight make something ~200c.... the melting point of (most) solder.

My understanding of how that can work is, the cracks that can form in the solder over time on a mobo are so tiny, that you can't even see them with the naked eye, so heating the solder to make those cracks better might not take so much heat, so the sunlight might work like the oven trick with GPUs, for example.

I have also fixed a GPU with an oven once, but it only lasted about a week or two and was bad again. That is probably because the fix is only temporary and the cracks can....well......crack again and reopen, so to speak, making the solder joints compromised again, and then tiny differences in voltages or resistance or whatnot from those joints start causing problems again.

So even metal like solder can get pretty hot in direct sunlight, if left there long enough. Just my thoughts.

[pbboi4u01]

İlk olarak The Giving One tarafından gönderildi:

İlk olarak Autumn_ tarafından gönderildi:

Except how could sunlight make something ~200c.... the melting point of (most) solder.

My understanding of how that can work is, the cracks that can form in the solder over time on a mobo are so tiny, that you can't even see them with the naked eye, so heating the solder to make those cracks better might not take so much heat, so the sunlight might work like the oven trick with GPUs, for example.

I have also fixed a GPU with an oven once, but it only lasted about a week or two and was bad again. That is probably because the fix is only temporary and the cracks can....well......crack again and reopen, so to speak, making the solder joints compromised again, and then tiny differences in voltages or resistance or whatnot from those joints start causing problems again.

So even metal like solder can get pretty hot in direct sunlight, if left there long enough. Just my thoughts.

I own my own jewelry designing company which is some of the most technical work you can imagine and requires a mastery of brazing/soldering....I can assure you that until you hit the melting point that solder no matter how small a crack, is doing nothing to make this the cause of the fix. my guess is it is a process that is using the sun/oven/heat to charge the positive ions within the battery core. same way putting a battery in the freezer increases the negative polarity and allows the battery to, for lack of a better term, increase its storage, albeit temporarily until heat causes it to retract or reduce storage by eliminating or melting the oxygen contained within the cell. now im going to google wtf the sun does for a dead mobo

[The Giving One]

İlk olarak pbboi4u01 tarafından gönderildi:

I own my own jewelry designing company which is some of the most technical work you can imagine and requires a mastery of brazing/soldering....I can assure you that until you hit the melting point that solder no matter how small a crack, is doing nothing to make this the cause of the fix. my guess is it is a process that is using the sun/oven/heat to charge the positive ions within the battery core. same way putting a battery in the freezer increases the negative polarity and allows the battery to, for lack of a better term, increase its storage, albeit temporarily until heat causes it to retract or reduce storage by eliminating or melting the oxygen contained within the cell. now im going to google wtf the sun does for a dead mobo

That's very informative and interesting. Thanks for the reply and polite correction, if you will. I will definitely take your word for it, as yes, I am sure that type of craft requires a mastery of brazing and soldering, among other talents.

[rx7t3_gio]

Nice info that can be really useful to many people.

[mmmm]

I just had this happen. Pressing the power button did nothing. Changing power supply did nothing. Replaced the battery: instant power up and boot.

AsRock Taichi x370 motherboard that I got in 2017. So the battery it came with lasted 6 years.

[Blueberry {JESUS IS LORD}]

i have a bad cmos battery ( it keeps losing time everytime the pc is unplugged) but i dont feel like changing it lol