Front Panel CMOS reset switch

Anyone know how to build a CMOS reset switch that can be installed onto the front (or back) panel of a computer? I'm sick of opening it up and switching the jumper when I overclock my computer too much.

CMOS reset is either a 2 or 3 pin connector on the motherboard.

If yours is one with three pins, you'll need a switch to change between 'normal' and 'reset'.

If yours is one with two pins, you can use any normal case button or a jumper with two long wires soldered to it. If you wanted to reset it you would just make the two wires touch each other.

You would need a Double Pole Double Throw switch (DPDT). My MSI motherboard has a 3-pin CMOS reset jumper. Pins 1-2 reset, pins 2-3 normal. DPDT switch position 1 normal, position 2 reset. You can get the switch at Radio Shack or any electronics supply

<shameless plug>
My new board auto-resets on failed OCing. I have no use of the CMOS jumper anymore. :rolleyes:
</shameless plug>

If I were you, I'd get 3 wires. Attach each one to its own pin. Then, just make a slider switch out of plastic or something. In 1 state it'll short pins 1 and 2, and in the other state it'll short pins 2 and 3. Then you can attach it to your case or something. The hard part being creating the slider itself...

Or... you could just run the 3 wires to the outside of your case and tape them. When you wanna clear the CMOS:
1) Remove tape.
2) Short other 2 wires.
3) Add tape.
4) Wait.
5) Reverse.
6)
7) Profit.

Hi MetalX,

a CMOS clear switch is definitely a lifesaver when overclocking

The easiest type of switch to mount is a "toggle" switch, because you only need to drill 1 small hole to mount it. the downside is that it is easy to accidentally switch it when you don't want to.

a "slider" switch or "rocker" switch will give a cleaner look and be more resistant to "accidental switching". the downside is that you will have to cut out a rectangular opening (as opposed to simply drilling a hole for a toggle switch).

In my current case, I mounted a DPST "slider" switch on an unused 3.5" drive bay cover. for the motherboard connector I used a standard 3-pin fan connector from an old case fan.



cheers :wave:

Nice work KingCody,
this is exactly what I was talking about

Oh, ok thanks. So I guess I should just go to Radioshack/The Source and get a slider switch with 3 pins on the bottom and connect it to the CMOS reset pins (3 pin)?

Yes MetalX,
just be careful not to short anything out. Use a little shrink tubing

What do you mean? What's shrink tubing and where does it need to be?

Shrink tubing is the blue stuff in KingCody's photo. Shrink tubing protects the solder joints and keeps the pins from shorting to each other and other metal in the case. Ask the people at Radio Shack, and do you know how to solder?

MetalX, I'm sure you can find the slider from somewhere else besides RadioShack, they charge about 40% more than most electronic websites. I saw a wireless nic card for ~$50 there.

No I don't know how to solder... We do have a soldering thing in the house somewhere... Do I NEED to solder?

Maybe so, but the one near me sells all kinds of switches for ~$3 CAD. Even if it is a 40% savings, that's only a little more than a buck. It's not really worth it... I can see your point if I was going to buy something more expensive (not including LCD monitors) though.

How do you expect to attach the wires to the motherboard and to the switch? Are you planning to use tape or glue? I hope not! Look again at Kingcody's picture. He used solder and shrink tubing properly

basically, yes. as I mentioned earlier it doesn't have to be a slider switch, it just has to have at least two [conductive] positions. a toggle switch is the easiest type to mount/install.

here is a nice DPST toggle switch from RadioShack that has a safety cover (to prevent you from clearing CMOS by accident )

solder and heat-shrink is the best way, but there are other ways that will work fine. if you get a switch like the one I linked above, it's connectors are flat "blades" with hole drilled in each one. there are a couple ways to attach the wires without soldering...

1. the easiest way is to use crimp-on connectors like this, then simply slide them into the "blades" on the switch.

2. the other "solder-less" method is to carefully thread the [stripped] wire through the hole in the "blade", fold it over and twist it around itself, then electrical tape it (cheap electrical tape will not stay wound in such a tight circle, so if you use this method then just fold the tape 1 making the adhesive sides stick together

:wave:

Kinda off topic, but sadly it's kinda hard to find a radio shack that actually sells electronic parts any more, at least where i live, they are all turning into mobile phone / satellite tv stores.

I only suggested Radio Shack because most people know them. A simple DPDT toggle switch can be purchased at most any hardware store too. Our Radio Shacks here all carry electronic parts

The RadioShacks near where I live are mostly cell-phone/speaker oriented, with a few digital cameras and lcd tv's.

Ok, thanks for the input guys, I just went to Radioshack and picked up a random toggle switch with 3 pins on the bottom. Got it working. Thanks!

How did you attach the switch wires to the motherboard CMOS/clear pins?

I used an extra 3 pin fan extension cable that came with my fan controller. I plugged one end onto the CMOS reset pins, and cut off the other end, then stripped the wires, and put them through the holes in the pins on the switch, and taped them all so that they wouldn't short.

Then I mounted the switch on the back of my case. Works perfectly. Although I must admit, the back of the switch doesn't look NEARLY as clean as KingCody's.

Mine is SUPPOSED to do that, but for some reason it never does... Besides, having a CMOS reset switch is good because you can use it when you get a new mobo so you won't fret about getting an auto reset mobo.