Restting the CMOS on P5B Deluxe

[morikal]

Ok, so in the manual it says:
1) Turn OFF computer and unplug power cord
2) Remove the onboard battery
3) Remove the jumper cap from pints 1-2 (default) to pint 2-3. Keep the cap on pins 2-3 for about 5-10 seconds, then move the cap back to pins 1-2.
4) Reinstall the battery
5) Plug the power cord and turn ON the computer
6) Hold tdown the <Del> key during the boot process and enter BIOS setup to re-enter data.

I am a little confused, and have had problems in the past with Asus boards resetting the CMOS.

Questions:
1) If I unplug the power cord and take out the onboard battery, what possible effect could moving a jumper for 5-10 seconds have? If there is no residual power at all in the board, how does this accomplish anything at all? Does the BIOS ROM have yet another power supply aside from the onbaord battery?

2) How do you uninstall the battery without damaging it? On my last Asus board I had to reset the CMOS after the CPU Recall thingie failed after an overclock attempt, and to get the battery out of the board I had to snap the plastic ring holding it in, and since then the battery wouldn't sit right and I had to hold it in with a plastic zip tie, and had problems after that with saving certain BIOS configurations.

The reason I need to do this is so I can upgrade to the 0711 BIOS, but I don't want to damage the board's battery again... and I don't understand why the jumper move is needed if the battery is already out...

 

[rwpritchett]

I think Asus' instructions are a bit overkill. Just shorting out the pins with the jumper is usually sufficient to clear the CMOS.

When I updated from 0706 to 0711, I didn't even clear the CMOS. I just updatd to 0711 via Asus Update within Windows. Upon reboot, the BIOS is at default settings. I usually don't clear the CMOS unless I am unable to get into BIOS after a flash. If it boots up, I don't bother.

 

[morikal]

Ok, but just in case all else fails, does anyone know how to remove and reinstall the battery without cracking the plastic casing?

 

[gqmracerx7]

Ok, but just in case all else fails, does anyone know how to remove and reinstall the battery without cracking the plastic casing?

There should be a small metal tab on the bottom. Press down on that and it, sometimes, pops the battery right out. Other times you'll a small screwdriver or blade to help it out while pressing the tab.

 

[croc]

A wee bit of overkill... Turning off the psu is a good idea, as then there's no chance that there is any power holding up the caps that may be helping to hold the bios memory.

As to removing the battery and also moving the jumper, without seeing the actual circuit design I can't do more than surmise that this is to keep the jumper from shorting out the battery as well as the caps.... Sensible in some designs. I don't think that you'll have any issues with doing that, but I've found that sometimes you also have to remove the gpu to do it.

Anyway, if that's what the manual recommends, (since neither you nor I are going to get a look at the circuit design) then that's what I'd do. As mentioned above, not usually necessary for a bios upgrade. May, however, be required for a bios downgrade or a re-flash.

A couple of MB's also have dual bios. You can back up your current bios to the 2nd bios, if your flash fails just copy the 2nd bios back over the primary bios. Of course, that's if you can get into the bios at all.

Kind of a longwinded way of saying 'do what the good book says'.