Can I resurrect a dead key?

Discussion in 'hardware' started by bellgamin, Jan 14, 2022 at 5:42 PM.

  1. bellgamin

    bellgamin Very Frequent Poster

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    I have an old but dearly beloved Dell laptop. Everything works fine except the CTRL key on the left side died. The CTRL key on the right side works but it's inconvenient for a right-hander like me. Is there a relatively easy way to revitalize a CTRL key or is it fixable only by a skilled repair person &/or a new keyboard?
     
    Last edited: Jan 14, 2022 at 6:04 PM
  2. imdb

    imdb Registered Member

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    are your laptop's keys detachable? if yes, did you try removing it and clean the switch?
     
  3. bellgamin

    bellgamin Very Frequent Poster

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    Per your suggestion, I gave it a try. Key was detachable. Removed it & cleaned it. No joy -- like bathing a cadaver.

    Years ago, during Korean war, I drove a Jeep daily over a dirt road that turned to mud when it rained, which was often. There was one stretch of road with REALLY deep mud -- we called it the Abyss. To get past it, you put your vehicle in 4-wheel & kept going no matter what. I always made it through except 1 time when the Jeep's engine died midway through the Abyss. A buddy came along, opened the hood, sprayed the sparks with WD40. It cranked right up & kept on going.

    WD40 for a dead computer key? Ummm... maybe not. :rolleyes:
     
  4. Krusty

    Krusty Registered Member

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    Contact cleaner?
     
  5. imdb

    imdb Registered Member

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    that's an interesting anecdote but i doubt wd40 would do the trick here. :D
    sounds like it needs a repair, by a qualified technician.
     
  6. act8192

    act8192 Registered Member

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    If it's electrical connection problem clean it with DEOXID from Amazon. Spray a tiny bit on a q-tip and clean the contact. And if you also happen to have a radio wiith a rotary volume control that crackles, Deoxit cures it. I have Deoxid D5.
    https://www.amazon.com/dp/B00006LVEU?psc=1&ref=ppx_yo2_dt_b_product_details
    If it's a matter of pushing through some membrane - perhaps 90% rubbing alcohol.
    And please, don't even think about WD40 :)
     
  7. bellgamin

    bellgamin Very Frequent Poster

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    @act8192 under the key cap was a solid plastic layer with a little thing sticking up in the middle. It offered no easy access to the electrical connection.
     
  8. Bill_Bright

    Bill_Bright Registered Member

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    Never use WD-40 on today's electronics. DeoxIT works fine with metal switches. I would not use it on plastic/carbon-pad switches as found with most laptop keyboards, and instead use a decent contact cleaner like CRC QD Electronic Cleaner. If you cannot expose the carbon pad of your CTRL key - well, getting used to the right-hand key may just improve your dexterity! ;)

    If that "little thing sticking up in the middle" looks like a small hockey puck, that could be the carbon pad acting as one contact point of the switch. If that solid plastic layer has a bunch of "dome" shaped reverse divots (for a lack of a better name), the insides of the domes would be the other contact of the switch.

    A cotton swab wet with CRC cleaner can clean the inside of the dome. Carefully using a "clean" pencil erasure to "erase" the top of the carbon pad (hockey puck) works great to clean that contact surface of crud. Blast the area clean of erasure crumbs and cotton fibers with a can of compressed dusting gas before reassembly.

    Note today's electronics use very low voltages, much in part to avoid arcs and sparks across gaps. The larger the gap, the greater the voltage must be to arc across that gap. Today's digital electronics have gaps in the transistor "gates" barely the width of a single atom. That's a tiny gap. So it takes very little voltage to arc across that gap.

    In computer systems, 12V is considered high. 12V is used to power drive and fan motors, but divided down to power other devices - often well below 2V.

    With a car's ignition system, you want the voltage to arc or spark across the spark plug gap (the Grand Canyon - microscopically speaking) and so a very large voltage is used - in the neighborhood of 40,000 to 100,000 volts is sent to the spark plug. That kind of voltage will easily vaporize any oily-based residue WD-40 leaves behind.
     
  9. bellgamin

    bellgamin Very Frequent Poster

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  10. Bill_Bright

    Bill_Bright Registered Member

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    Thanks and good luck.
     
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