S7 392 replacement keyboard defective?

IdahoDan
IdahoDan Member Posts: 6 New User
edited November 2023 in 2020 Archives
The keyboard was damaged by using an all-purpose cleaning spray.  Some of the keys didn't work at all.  I replaced it with a keyboard I found on Ebay: https://www.ebay.com/itm/New-Acer-Aspire-S7-391-S7-392-Silver-Backlit-Laptop-Keyboard-NK-I1113-02L-USA/282606466287?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

On the new keyboard, the keys only work if you press firmly and directly in the center.  If I press a key from the edge, it feels normal, clicks down, but no keystroke is registered.  Does this sound like a defective keyboard or did I damage something possibly in the install?  Anyone seen anything like this before?

I don't consider this keyboard usable, so I'll either try to install another keyboard or trash the laptop.  But I don't want to buy another keyboard and go through that hellish install, if I will just have the same result.

Best Answer

  • JackE
    JackE ACE Posts: 45,211 Trailblazer
    Answer ✓
    Re-seat the KB's mainboard connector a few times to help clean its contacts just in case some moisture got in there. If still no joy, I might be tempted to back off on the 53 screws to see if the keys start to respond better. The KB itself is flimsy and may be distorted from all those screws. If these measures don't work but all the keys register when pressed directly in the center, then yes I think maybe you got a lemon KB. But since every key seems to behave this way, I'd  be worried that all the KBs from this supplier might be lemons. I'd probably ask for a refund and try another supplier. Jack E/NJ

    Jack E/NJ

Answers

  • JackE
    JackE ACE Posts: 45,211 Trailblazer
    >>> The keyboard was damaged by using an all-purpose cleaning spray>>>

    What's brand name of the all-purpose spray? Jack E/NJ

    Jack E/NJ

  • IdahoDan
    IdahoDan Member Posts: 6 New User
    JackE said:
    >>> The keyboard was damaged by using an all-purpose cleaning spray>>>

    What's brand name of the all-purpose spray? Jack E/NJ
    Field Day All Purpose Cleaner (Free & Clear).  Kind of irrelevant though I think.  I replaced the keyboard with a new one.  And the old keyboard is damaged beyond repair after taking it out.  I had to use a dremel to take out half of the 50+ micro screws securing the keyboard after they stripped on the screwdriver.
  • JackE
    JackE ACE Posts: 45,211 Trailblazer
    FieldDay is an alkaline water-based surfactant spray formula which will corrode KB contacts under the key covers because it doesn't evaporate quickly and leaves a hygroscopic residue when it does.  The issue now  is if this spray got under the old KB to reach the mainboard and its connectors. Did you spray the old the KB directly or spray a cloth then wiped the key covers? Jack E/NJ   

    Jack E/NJ

  • IdahoDan
    IdahoDan Member Posts: 6 New User
    JackE said:
    FieldDay is an alkaline water-based surfactant spray formula which will corrode KB contacts under the key covers because it doesn't evaporate quickly and leaves a hygroscopic residue when it does.  The issue now  is if this spray got under the old KB to reach the mainboard and its connectors. Did you spray the old the KB directly or spray a cloth then wiped the key covers? Jack E/NJ   
    That is very interesting.  Wife says she sprayed it directly, then wiped.  So it is possible that the liquid made its way past the keyboard to the mainboard.  I still don't understand how it would cause the current behavior though, even if the mainboard was damaged.
  • JackE
    JackE ACE Posts: 45,211 Trailblazer
    Answer ✓
    Re-seat the KB's mainboard connector a few times to help clean its contacts just in case some moisture got in there. If still no joy, I might be tempted to back off on the 53 screws to see if the keys start to respond better. The KB itself is flimsy and may be distorted from all those screws. If these measures don't work but all the keys register when pressed directly in the center, then yes I think maybe you got a lemon KB. But since every key seems to behave this way, I'd  be worried that all the KBs from this supplier might be lemons. I'd probably ask for a refund and try another supplier. Jack E/NJ

    Jack E/NJ

  • IdahoDan
    IdahoDan Member Posts: 6 New User
    JackE said:
    Re-seat the KB's mainboard connector a few times to help clean its contacts just in case some moisture got in there. If still no joy, I might be tempted to back off on the 53 screws to see if the keys start to respond better. The KB itself is flimsy and may be distorted from all those screws. If these measures don't work but all the keys register when pressed directly in the center, then yes I think maybe you got a lemon KB. But since every key seems to behave this way, I'd  be worried that all the KBs from this supplier might be lemons. I'd probably ask for a refund and try another supplier. Jack E/NJ
    Thanks Jack.  I'll mark this as the answer, though I'm not sure I will go thru with the keyboard replacement again.  I'd have to find new screws somehow and a lot of those holes are now stripped too.  But I've learned a lot at least.
  • JackE
    JackE ACE Posts: 45,211 Trailblazer
    New screws are fairly easy to replace with an Amazon laptop screw assortment kit. Less than $10 for more laptop screws than you'll know what to do with in a lifetime.. However, I'd be inclined to use way less than half on the S7. I think 50+ screws to affix a keyboard is way overkill. Newegg has the bare KB for about $30 so I'd probably go with that. Jack E/NJ

    Jack E/NJ

  • IdahoDan
    IdahoDan Member Posts: 6 New User
    I took your advice, and bought the kb on Newegg.  But finding these screws turned out to be really, really hard.  They are literally the smallest screws sold on the internet from what I could tell.  The closest thing I could find were on Ali Express from China, but it turned out the heads were not wide enough.  No matter, I was able to re-use enough of the original screws.

    I have success (mostly)!  The right shift key doesn't work, but for its new purpose as a machine for my kindergartner to do remote learning, it will be fine.  I think that first replacement keyboard must have been defective.  

    Thanks so much.  I would have given up on this thing if not for you.
  • IdahoDan
    IdahoDan Member Posts: 6 New User
    For anyone checking this thread, that Amazon kit does not have the screw size specified in the manual.  The manual specifies M1.2 x L1, quantity 53!  https://www.manualslib.com/manual/483193/Acer-Aspire-S7-391.html?page=97&term=keyboard&selected=29

    So good luck.  My advice is use a PH00 or even PH000 screwdriver, and pray you don't strip it.  If you do, cut a shallow slot with a dremel to get it with a flat blade screwdriver.  This will destroy the keyboard, but if you got this far, you're probably replacing it anyways. Try to retain as many screws as you can.  Jack probably has better advice than me ;) , but this is what worked in my case.