Front Panel CMOS reset switch

By MetalX
Jan 20, 2007
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  1. 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.
  2. Jesse_hz

    Jesse_hz TechSpot Maniac Posts: 638

    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.
  3. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    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
  4. agi_shi

    agi_shi Newcomer, in training Posts: 507

    <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.
  5. KingCody

    KingCody TechSpot Guru Posts: 1,568   +7

    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.

    [​IMG]

    cheers :wave:
  6. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    Nice work KingCody,
    this is exactly what I was talking about :)
  7. MetalX

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    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)?
  8. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

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

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    What do you mean? What's shrink tubing and where does it need to be?
  10. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    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?
  11. cfitzarl

    cfitzarl TechSpot Chancellor Posts: 2,520   +9

    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.
     
  12. MetalX

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    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.
  13. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    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
  14. KingCody

    KingCody TechSpot Guru Posts: 1,568   +7

    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 ;))
    [​IMG]

    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:
  15. gavilan

    gavilan Newcomer, in training Posts: 136

    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.
  16. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    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
  17. cfitzarl

    cfitzarl TechSpot Chancellor Posts: 2,520   +9

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

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    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! :D
  19. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

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

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    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.
  21. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    That was a great idea using the fan connector
  22. MetalX

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    Thanks, but I think that's what KingCody did too... at least that's what I remember reading in his picture of his case in the Gallery. That's where I got the idea so thank KingCody lol :)
  23. KingCody

    KingCody TechSpot Guru Posts: 1,568   +7

    your welcome, I'm glad to see you got it working. it is so simple, yet so very useful to have. makes you wonder why more "enthusiast" cases don't have them built in already.

    I don't think I would even bother overclocking if I had to open up my case to reset CMOS... heck I'm so lazy that even a switch on the back of the case is too far for me ;)

    cheers :wave:
  24. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,744   +156

    "I don't think I would even bother overclocking if I had to open up my case to reset CMOS... heck I'm so lazy that even a switch on the back of the case is too far for me"

    I know what you mean KC. My case is on the floor. I have to crawl under my desk to get to it. It's a full-tower server case, so it is easy to work on... Thank goodness!
  25. MetalX

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    Lol, my case is on my desk and it's not very cluttered at all. So it's pretty easy to reach the switch on the back. In fact I barely even need to stretch my arm to get to it.
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