Question how to clear cmos w/o removing battery & don't have that small clip to jumper

[LOUISSSSS]

Is there a way to clear the CMOS w/o removing the battery?

i don't think I have that small connector clip that usually is used to clear the CMOS. Is there another way?

let's say I find the clip, what's the best (only) way to clear the CMOS in this case?

 

[Blazer7]

You can use anything metallic to short the clear CMOS jumper. I often use a screwdriver for this. Just hold it there for a couple of seconds. That will be enough.

 

[Qbah]

Originally posted by: Blazer7
You can use anything metallic to short the clear CMOS jumper. I often use a screwdriver for this. Just hold it there for a couple of seconds. That will be enough.

:thumbsup:

I remember I had a rig once without the case, was laying there happily on some newspapers. I was starting it with a screwdriver - was shorting the pins for the on/off button

 

[Billb2]

NO, you have to remove the battery. It supplies power to the BIOS eprom and as long as the eprom is powered it won't reset. Also, some motherboard/PSU combinations (newer) will supply power to the BIOS even with the battery removed, so you have to unplug the PSU from the wall outlet too.

You don't have a jumper! I can't believe that!

 

[LOUISSSSS]

so to correctly do it w/ a flathead screwdriver, i would:

1. turn off pc
2. touch both pins w/ flat screwdriver
3. turn on pc while they're touching
4. cmos will be rest

am i right?

 

[NXIL]

NOOOOO!!!!!!!!!!!!!!

Louis, do NOT turn the PC on with the CMOS pins shorted!!!!!!!!!!!!!!!!!!!!!!

That can fry the mobo.

Procedure:

unplug PC.

Find CMOS jumpers; use flat screwdriver to short them out, i.e. touch both of them.

Note: there is dispute about removing the battery. I personally feel that it is, in fact, better to remove the battery when doing this--and, on some mobos, have had to leave battery out for an hour or two....but, that will probably not be necessary.

After shorting out jumpers, replace battery, plug PC back in, and you should have a wiped out CMOS with a date from a few years ago as the current time....

HTH

NX

Note: should be explicit instructions in mobo manual....

edit: spelling

 

[Forumpanda]

As far as removing battery goes, I usually just give it a try without first, at least on some mobo's it can be a pain to get to the battery without taking everything out first.

and yes I also 2. that last post, sometimes I have had no success resetting even with the battery out, but leaving it out for a few hours solved it.

 

[LOUISSSSS]

-i see, so leaving out for 5-10 mins wont really clear everything right?

 

[illvm]

Turning on the mobo with the jumpers shorted could really fry the mobo? I thought most procedures for shorting out the CMOS jumpers and resetting the CMOS required the PC to power on (although it wouldn't POST or do anything other than reset the CMOS).

 

[LOUISSSSS]

zzz for slow or no AT responses. looks like this forum is dead

 

[NXIL]

zzz for slow or no AT responses.

Lakers/Orlando game?

Turning on the mobo with the jumpers shorted could really fry the mobo?

I have read that in motherboard manuals, so yes, I do believe that is true.

-i see, so leaving out for 5-10 mins wont really clear everything right?

I don't think so; I think it has to be left out for a while; for me, at least on one occasion, overnight. In theory, that is not supposed to happen, but, in practice, it does.

What mobo are you clearing CMOS? Usually very clear directions, step by step, in manual, with warnings, such as the "Don't turn it on with pins shorted" warning....

NX

 

[Modelworks]

The correct way to reset the cmos is to unplug the pc, remove the battery, then short the jumper for a few seconds. That is the only 100% sure way not to cause damage.
Some motherboards supply power to the cmos from the +5v standby and only use the battery when AC power is not available. If you short the jumper on such a board you can blow an on board fuse , some have resettable fuses, some do not. Shorting the jumper on boards that do not use standby voltage to power the cmos , but use the battery, is a bad idea also when not removing the battery. If you have to do it with the battery in place, do it for just a second, do not leave the jumper in place. The cmos batteries are lithium based and can cause a fire if shorted.

Some of the newer boards it does not matter if power is on, off , battery, etc, but these are rare. Instead of shorting the power, they use the erase enable pin that some of the newer flash chips support.

Never put your hands inside a pc case that is powered on, that is just a bad idea for so many reasons.

 

[just4U]

wow..

I always just clear the cmos with the jumper pins. Can remember doing that for atleast 5+ years. I don't recall having to take the battery out.. ever. and that's on atleast 40+ motherboards.

You can find jumpers on old boards, or hard drives as well if you have any sitting around.

 

[PingSpike]

What is all this business about frying motherboards and your PC exploding if you breath on the wrong pins here? I've never even heard a antecdote of any of that happening, much less read any warning as such. And while this certainly doesn't prove its crazy, I've started up a plethora of asus motherboards that shipped with the cmos jumper in the clear position. They worked fine once I figured out what was going on. No fires. No exploding batteries.

You will have a cmos jumper...I suppose its possible an older motherboard may not have one but I have certainly never seen or heard of such a beast. My abit board has a smartypants button on the back that clears the bios but I believe it also still has a jumper. Unplug the PC, don't just turn it off and short it some how. I've heard the clear sometimes doesn't happen unless its in that position for a minute or two...I've never been patient enough to wait that long. Failing that, just remove the battery entirely. Its kind of a pain to do though, I'd just try to find a jumper. They're all over old hardware...expansion cards used to be littered with them before the days of plug and play stuff. I find it odd you're missing the jumper though, its usually there and set to the non-clear position...cmos is typically a 3 pin block with therefore only two settings...the one its not on is clear.

I've started PCs with a screw driver short before, but I wouldn't actually recommend this unless you have pretty steady hands.

But don't turn the PC on with a screw driver shorting it...thats not really the goal anyway. You're trying to cut power to cmos so that it loses all its settings. The settings are stored in a piece of ram that is kept from clearing by battery power when the PC is off. You want no power going to this thing.

 

[NXIL]

Hey Pingspike,

What is all this business about frying motherboards and your PC exploding if you breath on the wrong pins here?

It's true. And your dog will get fleas, and your cat will no longer land on its feet.

I've never even heard a anecdote of any of that happening

QED. Anecdote = true. Kid got a vaccine; kid developed autism. Therefore, vaccines cause autism. And, Jenny McCarthy says this is true.

Misuse of anecdotal evidence is a logical fallacy and is sometimes informally referred to as the "person who" fallacy

http://en.wikipedia.org/wiki/Anecdotal_evidence

Regardless, here are CMOS clearing instructions from manuals of mobos I have:

From my Tyan mobo's manual:

How to clear the CMOS data

- Power off system and disconnect power
supply from AC source (Tyan's emphasis)

- Use jumper cap to close Pin_2 and 3 for
several seconds to Clear CMOS

- Replace jumper cap to close Pin_1 and 2

Reconnect power supply to AC source

Power on system

Asus:

Turn OFF computer, unplug power cord
Remove the onboard battery
Move jumper pin from 1-2 to 2-3 for 5-10 seconds, then return to 1-2
Reinstall battery
Plug in power cord, turn ON computer

Note: do not move cap on CLR CMOS pins from default position unless clearing CMOS; doing so will cause boot failure. And your cat will lose its hair.

OK, I added the part about the cat.

Sticking a metal screwdriver into computer case while it is powered up: probably not a good idea for most people.

http://www.darwinawards.com/

In today's news, from ABC Medical:

http://abcnews.go.com/Health/P...tory?id=7788538&page=1

How dangerous could that laptop, desktop, or Mac sitting in front of you be?

Photo: ER visits due to computer injuries

The first report to count computer-related emergency room injuries shows that each year more and more Americans are tripping over cords, dropping monitors, banging heads and snagging limbs.

Of course, we should ban computers, for safety's sake.

And soda:

http://health.yahoo.com/news/h...usemuscleproblems.html

Drinking too much cola can increase the risk of a muscle problem called hypokalemia, experts warn.

The second pregnant patient, who'd consumed up to seven liters of cola a day for 10 months, had low potassium levels

Pregnant. 7 liters of cola. Pregnant. 7 liters of cola. Does not compute.

By the way: no proof that the cola dropped the potassium level: anyone who drinks 7 liters of cola a day while pregnant is ignorant of basic nutrition; really ignorant. K+ is a nutrient, found in fresh fruits and veggies: could be all that soda displaced good foods, and the low K+ was a secondary effect, not primary. (Lots of alcohol: low B vitamins, but, that is also nutritional generally, not a direct effect of alcohol: all those calories from ethanol, and you don't need to take in other foods and nutrients.)

There are ANECDOTAL reports of people frying mobos by powering up with CMOS in CLR position:

http://www.ocforums.com/showthread.php?t=77615

http://www.nvnews.net/vbulletin/showthread.php?t=125786

Interesting: Lenovo says to power up with the CMOS CLR jumpered for clear:

http://www-307.ibm.com/pc/support/site.wss/MIGR-52235.html

From 2006:

http://newsgroups.derkeiler.co.../2006-08/msg01049.html

If a user uses the clear CMOS jumper, with the +5VSB present, it can actually physically burn one of the two diodes inside the three-legged dual diode (K45 type). I have helped at least one person to repair their board after damaging it that way - they managed to solder two ordinary diodes in place of the burned three-legged device.

Therefore, since the design method for each clear CMOS implementation is unknown, but because there is a known design defect in a large number of motherboard types, it pays to unplug the computer so that there is no chance of +5VSB being present when the jumper is used.

So, in summary:

• 
  Loiussss can check his motherboard's manual, specific instructions will be there.
  
  Missing jumper? Find one on old hard drive, or, use screwdriver to short pins.
  
  Do this with the power cable unplugged.
  
  Don't get tangled in your computer's cords or cables. If you do, and you hurt yourself, call a lawyer:
  
  http://www.attorneyatlaw.com/2...dents-researchers-say/
  
  You can get money for injuring yourself, because you left cables out and tripped over them.
  
  And, if you stick a screwdriver into your powered PC case, you (or your heirs) might even get more, since there is no warning on your motherboard not to do that.
  
  Take battery out when jumping pins? I do....others don't.
  
  Your mileage may vary.

I am glad that we solved this.

Next: settlements in the occupied West Bank, the future of GM and Chrysler, health care (for computer injuries), racial and religious intolerance: having solved the CMOS CLR issue, we should be able to knock the rest of those out by Friday.

NX

 

[NXIL]

Louisss lists a Gigabyte EP45-UD3R as his mobo.

From the manual for this mobo:

http://www.gigabyte.us/Support...pe=Manual&FileID=18786

Page 32:

21) CLR_CMOS (Clearing CMOS Jumper)

Use this jumper to clear the CMOS values (e.g. date information and BIOS configurations) and reset the CMOS values to factory defaults.

To clear the CMOS values, place a jumper cap on the two pins to temporarily short the two pins or use a metal object like a screwdriver to touch the two pins for a few seconds.

Always turn off your computer and unplug the power cord from the power outlet before clearing the CMOS values.

? After clearing the CMOS values and before turning on your computer, be sure to remove the jumper cap from the jumper.

Failure to do so may cause damage to the motherboard.

? After system restart, go to BIOS Setup

And: p 33:

You may clear the CMOS values by removing the battery:

1. Turn off your computer and unplug the power cord.

2. Gently remove the battery from the battery holder and wait for one minute. (Or use a metal object like a screwdriver to touch the positive and negative terminals of the battery holder, making them short for 5 seconds.)

3. Replace the battery.

4. Plug in the power cord and restart your computer.

? Always turn off your computer and unplug the power cord before replacing the battery.

NX

 

[zagood]

heh...I like nx.

I found myself clearing my cmos over and over again recovering from bad overclocks and wanted to make an external clear cmos button...I figured I could crank them out and sell them to you guys. Then I saw Silverstone already did...you might want to check it out.

http://www.silverstonetek.com/...pno=CLEARCMOS&area=usa

those jerks.

-z

 

[Sheninat0r]

You can just hook up any switch with a 2-pin header and plug it into your CMOS clear pins - when you need to clear CMOS, just press the switch/toggle the rocker back and forth and voila.

 

[Modelworks]

Originally posted by: PingSpike
I've never even heard a antecdote of any of that happening, much less read any warning as such. And while this certainly doesn't prove its crazy, I've started up a plethora of asus motherboards that shipped with the cmos jumper in the clear position. They worked fine once I figured out what was going on. No fires. No exploding batteries.

The reason is that the advice you are giving is only based on your experience . It is like the people who talk about jump starting cars in the rain and laugh at the idea of getting electrocuted, I've done it plenty of times so that means its okay to do it !


Will it cause a fire or explode ? Probably not, but can it ? Absolutely.