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Repairing a laptop keyboard?

Discussion in 'Computers' started by Mayhem, Jul 30, 2012.

  1. Mayhem

    Mayhem Android Expert
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    My kids got my old Dell Inspiron 1545 laptop when I got a new one and have somehow managed to make it to where one of the keys no longer works. I've already re-seated the cable as well as pulled the key and hit the spot with compressed air. Still no dice.

    Anyone know how to get it apart? The bottom of the keyboard is covered in aluminum. I know from past experience with other PCB issues in other devices that hitting the spot with rubbing alcohol will do the trick.

    Yes, replacement keyboards are cheap ($23) but it seems kind of a waste to plunk down money when it's a single key.
     

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  2. Speed Daemon

    Speed Daemon Android Expert
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    One thing about laptop keyboards is that they're thin and flimsy, and fetting more so by the minute. If the bad key has physical damage, the only repair that will work is to replace the whole keyboard. (The price isn't that bad.)

    If you really want to do what you can to revive the old keyboard, remove it from the laptop, prepare a cooking dish (or some other container large enough to hold the entire keyboard) with warm soapy water, and soak the keyboard in it. Gently agitate the keyboard to allow the solution into all tight spaces, and to dissolve any stuff that might be keeping the electrical contacts from closing. While submerged, press all buttons, especially the bad one.

    After that, remove the keyboard and rinse under lukewarm tap water. Again, agitate it and press buttons to allow fresh water in and gunk out. Replace the soapy water in the dish with fresh clean water, preferably distilled water. Repeat with the clean or distilled water. Finally, pull out the keyboard and rinse with distilled water. (If you don't have distilled water, but have a drinking water purifier, use water run through that filter.)

    Use towels to soak up whatever water you can shake out of the keyboard, again agitating it and pressing keys. After you've shaken as much water as you can out, let it stand in a warm dry place for a couple of days to evaporate the rest of the water. Pressing every key from time to time can help speed up the process.

    Finally reinstall the keyboard and see if it works any better.
     
  3. johnlgalt

    johnlgalt Antidisestablishmentarian
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    I always used vinegar instead of soap water, and the sink (makes for easy drainage and disposal of the crud) but nice write up nonetheless.
     
  4. MacFett

    MacFett Android Expert
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    Have you tried popping another key off and moving the little disc thing that makes contact between the key and the board? Maybe the one on the bad key is FUBAR.

    And if I was going to wash a keyboard (and I wouldn't) I would hit it with some isopropyl alcohol to evaporate any moisture. Not rubbing alcohol, which has oil in it.
     
  5. SUroot

    SUroot Android Expert
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    I'd replace the keyboard. These things are all over eBay for the price of a Starbucks coffee
     
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  6. Bob Maxey

    Bob Maxey Android Expert
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    Be careful.

    Some PC boards contain components that do not like water. Some relays, for example, have holes that let the water in. Some pastes used to secure components are water based and water can lead to corrosion. A little of that, and your KB is not repairable.

    Water can affect the tiny fingers inside connectors and it will take some time to dry it out.

    My advice is to replace the KB. If it is inexpensive, why take the chance?

    I just asked Mr. Google and prices range from $12.00 to $25.00.
     
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  7. Speed Daemon

    Speed Daemon Android Expert
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    I can't say that I've ever seen a relay of any type on a keyboard, but if it lets water in, it lets water out as well.

    I don't know about water-soluble adhesives. I'm doubtful because ever since Freon was banned, water has been the solvent of choice for cleaning computer boards.

    As SUroot said, replacement keyboards are as cheap as a cup of coffee, so there's no big risk in trying.

    It should go without saying that it's not a good idea to dunk an entire laptop in water. But since that's not what we're talking about...
     
  8. Bob Maxey

    Bob Maxey Android Expert
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    Once water enters a component, no amount of drying will rid the part of H20 in a timely manner. I do not know if there are relays on a KB either. I really can't tell until I see the board. Just saying, be careful.

    The problem with water is it can corrode and degrade some parts. Minerals can leave deposits that can cause issues. Since a keyboard tends to be loaded with little switches, there could be a problem. And again, until I see the PCB, I cannot say.

    The advice to replace the bad board with a new part is sound advice. Especially if it is cheap. Or, try to repair the KB and if you have problems, then buy a new part.

    Perhaps some assemblies are cleaned with freon, but having spent a decade or more building consumer electronics, (and spending my time these days writing technical documentation) I can tell you we never used freon to clean boards. PCBs roll from the surface mount pick and place to the ovens, then the in-circuit testers, assembly and final test. No cleaning needed.

    Some manufacturers might use freon, but many use products like Solvon. Some probably still use an aqueous system. We used an aqueous system to clean reworked boards. We discovered just how bad a little water can be when we reworked thousands of Megahertz Pocket Modems. Fubar was the word of the day

    It really depends on the manufacturer.
     
  9. 350X

    350X Android Expert
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    keyboard contacts are like a set of points, they can get dirty and lose contact.

    even a remote for a TV can use a contact cleaning after many years.

    use a qtip n alcohol to clean.
     
  10. Speed Daemon

    Speed Daemon Android Expert
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    With all due respect, there's nothing useful to causing unnecessary hysteria, or by giving misleading "facts". Water does not have magical properties, good or evil.


    No, that's completely false. In fact, water is the reference substance by which we define neutral pH.


    Hence my advice to use distilled water.


    As I said, that was long ago. Before you were born probably.


    I hope that you can understand that a keyboard (the object of the topic) is not a Megahertz Pocket Modem, and therefore your anecdote isn't likely to apply to the topic at hand.

    "Throw away and buy new" is a choice that many people have very good reasons to eschew. Conservation is one very good reason. Another is to keep something that's no longer made. The bottom line is that the OP asked a question about refurbishment, not replacement: "Yes, replacement keyboards are cheap ($23) but it seems kind of a waste to plunk down money when it's a single key."
     
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  11. Bob Maxey

    Bob Maxey Android Expert
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    Water contains minerals. We had to use special water in our aqueous systems because of the minerals. Some manufacturers still use such systems. Those minerals FUBAR certain parts. This is indeed a fact despite your thoughts. I spent considerable time building consumer electronics and I dare say, I know a bit more about it than you, apparently.

    Be it a controller for a washing machine, a modem, a PDA a cellphone or MP3 player, electronics are electronics and they are made exactly the same way. Same production methods, same components, same SMT and ovens same solder baths. Trust me on this, I ain't no dummy.

    This is not old information. I am a technical writer and I spend my days teaching people how to avoid issues.

    And I know what the OP asked. Sometimes, it is simply better to replace rather than repair. This is obvious. Yes, you can try to fix it. In fact, I believe I suggested trying a repair first. then I suggested replacing the bad part because the cost was so low.

    You can call me out on other topics if you think you know best, but forget trying to one up me when it comes to manufacturing. I know my stuff; I prove it daily.
     
  12. Mayhem

    Mayhem Android Expert
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    So I hit the spot with rubbing alcohol and made it worse. Not sure why as I've used this method multiple times over the years to clean contacts on other PCBs.

    Oh well. Like I said before, I can always get a replacement for $23 online.
     
  13. Bob Maxey

    Bob Maxey Android Expert
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    Sometimes, alcohol also removes coatings near the component and the liquid mucks up the contacts. Sometimes, water does this as well.

    Good luck on the replacement.
     
  14. SUroot

    SUroot Android Expert
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    I'm sorry... water IS corrosive to MOST metals. Pure water less so. But not often is pure water encountered
     
  15. justintimber

    justintimber Lurker
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    Certainly you don
     
  16. Speed Daemon

    Speed Daemon Android Expert
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    Sorry but water is not only neutral, it's the definition of neutral. Somebody must have forgotten their Chem. 101.

    Of course "tap water", which of course is more than just water, can contain some impurities, but rarely are any of these impurities highly reactive. The biggest concern with using tap water is the non-reactive solids that might get left behind. That's why I always recommend a final rinse with distilled water. At less than a dollar a gallon, anyone in doubt can simply use only distilled water.

    It's really not that big a deal. If you want to exercise unusual caution, you're going to replace the whole keyboard anyway.
     
  17. Speed Daemon

    Speed Daemon Android Expert
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  18. Bob Maxey

    Bob Maxey Android Expert
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    I removed a key (tab, for those that care) by following what Mr. Google told me to do. Thing is, the key is made up of the key top, an internal plastic part and a springy like thingy. Not at all what I suspected.

    So if you want to clean parts like keyboard keys, find a set of drawings for your computer. You might find re-installation useful.
     

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