Solved Clearing CMOS Doesn't Reset System Time (RTC)

February 4, 2017 at 17:25:59
Specs: Windows 7, AMD A10 / 8GB
I've recently discovered this quirk of my Asus A68HM-PLUS mainboard: I wanted to install an OS on my computer so I jumped the CLEAR CMOS pins and popped the CMOS battery out overnight to reset to factory settings (I always do this before a fresh installation). About six hours later, I removed the jumper, replaced the new battery and powered up the computer. The settings cleared just fine and the date went back to January 1. But the system time was set to something random, not midnight like with my other mainboard. Is this something I need to worry about or is this normal for newer boards? I ran a check on an older (non-UEFI) BIOS board and everything reset, including the system time. I had to ask myself how the Asus kept any clock info at all, even if it was completely wrong.

message edited by Ratatouille


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✔ Best Answer
February 5, 2017 at 21:35:03
The bios reset will revert the clock back to the date shown in the bios firmware as its start or creation date, which usually won't be 00:00:00 as was the case with older bios'. I've never paid much attention to the time after resetting the bios but if it's not going to midnight then it's possible a specific time is also recorded in the firmware.

But if you think something screwy is going on with it you can check the motherboard support page for a bios update and if one is available, carefully install it.



#1
February 4, 2017 at 18:41:35
I don't know the reason but I can tell you this, you do NOT have to use both the jumper AND remove the battery & you do NOT have to wait for hours. All you need to do is unplug the power cord, move the jumper from the normal position to the clear position, wait a second or two, then move it back. The BIOS will reset to defaults. Why you would do this every time you change or reinstall the OS is beyond me. The only thing I can think that you might have done wrong was leave the power connected when you did the reset.

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#2
February 4, 2017 at 19:14:25
Hi Riider, thanks for the reply. I don't normally do both, just move the jumper like you said for a couple of seconds usually does the trick. A lot of my equipment I buy refurb so, as a habit, I always clear CMOS. This time, with a new board, I noticed the time was set to something random (but like I said, date and system settings were reset). I got curious and decided to see if taking out the battery for a few hours would make a difference. I repeat: I do not do this on a regular basis! It would be much too time-consuming.
I followed the same procedure I've always used by switching off the power supply and disconnecting the power bus from the mains. It just seems this board doesn't want to set the time to midnight like all my other ones do. It might not seem like a big deal but I did notice it. Hoping someone out there can shed some light on this for me.

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#3
February 4, 2017 at 21:10:23
Why on earth are you doing this in the first place?

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#4
February 5, 2017 at 21:35:03
✔ Best Answer
The bios reset will revert the clock back to the date shown in the bios firmware as its start or creation date, which usually won't be 00:00:00 as was the case with older bios'. I've never paid much attention to the time after resetting the bios but if it's not going to midnight then it's possible a specific time is also recorded in the firmware.

But if you think something screwy is going on with it you can check the motherboard support page for a bios update and if one is available, carefully install it.


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#5
February 6, 2017 at 05:33:05
Good to know. Thanks, DAVEINCAPS.

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#6
February 6, 2017 at 21:08:42
You're welcome. It's probably nothing to worry about.

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