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Old 10-04-2009, 05:35 PM   #1 (permalink)
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Default Clearing CMOS

Hi all.

I've had various motherboards through the years and have cleared CMOS's before. The board I have right now is: Gigabyte, model # EP35C-DS3R.

I was at a different tech forum elsewhere on the 'Net, and there's specific info there on my motherboard. I just want to be sure of something before I try it.

When I've cleared the CMOS before on various boards I've had, I usually just short out those two pins with a "jumper", or, just touch the two pins with a screwdriver tip. Now here's a quote from some info I've found on my motherboard:

"Once you have found these jumper pins you will need to get a Hard Drive or Optical Jumper (The same type you used to use on IDE Drives) and place this jumper on the 'Clear CMOS' pins. Then press and hold the Case Power on switch for a minute."

When I've cleared the CMOS before, I haven't pressed the Case Power switch in addition to putting the jumper on the two pins. Was I shortcutting things by not pressing the power button?

And does pressing the power button with the jumper on the pins "hurt" the CMOS battery? Because more info that I found goes on to say:

"You may also want to remove the CMOS battery. This is optional and not Always necessary, but you may want to try it if you are having issues getting the CMOS Cleared."

If I remove the CMOS battery, then is it really necessary to put the jumper on the pins and press the power button?

Because then there's this info, too:

"Now let the computer rest with this jumper on for 10-20 Minutes, this will ensure that the battery gets drained, and the CMOS is cleared. Some people will tell you it will only take a few seconds or a minute or two, but I find that to be false and it may indeed lead to a corrupt BootBlock and or a Bricked motherboard."

Did you catch the phrase used that goes "...this will ensure that the battery gets drained...". Does this mean "drained" as in the battery will now be "dead" and you need to get a new battery?

I'm looking to do a little overclocking, and I want to clear out the CMOS, set the "Load Optimized Defaults", and then start tweaking from there.

Please let me know, though, about the CMOS issue. I want to do it the best and most thorough way possible. And if "drained" means "dead", I suppose I could always go and buy another CMOS battery; they're not that expensive.

Thanks for any helpful info.

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Old 10-04-2009, 08:04 PM   #2 (permalink)
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Default Re: Clearing CMOS

This is what you should do:

1. Unplug the power.
2. Take out the CMOS battery OR short the CMOS pins
3. Press the case power on switch a few times
4. replace the battery OR stop shorting the CMOS pins
5. plug in the power again.

This will NOT drain the CMOS battery, the reason you need to press the power button a few times is to drain residual charge from the system. If you don't it's possible that the CMOS won't be cleared.
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