#5658 NORM Ship.2: Sticky Alt Key

[Zarro Boogs per Child]

#5658: Sticky Alt Key
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  Reporter:  davidpfarrell  |       Owner:  wad      
      Type:  defect         |      Status:  new      
  Priority:  normal         |   Milestone:  Ship.2   
 Component:  hardware       |     Version:  Build 650
Resolution:                 |    Keywords:           
  Verified:  0              |    Blocking:           
 Blockedby:                 |  
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Comment(by legutierr):

 Might this be a moisture/condensation issue?

 I had this problem when I first got my laptop, but it was very infrequent,
 and it would also resolve itself after a reboot.

 Then two days ago, as I was trying to update to build 653 using a USB, I
 was drinking a cold drink and some condensation dripped onto my space bar
 and track pad.  I blotted it up very quickly, but after rebooting with the
 new build my keyboard stopped working correctly (I soon realized that it
 was acting like it had a stuck alt key).  At first I assumed that the
 problem was related to the installation of 653, so I downgraded using the
 USB to 650.  But that didn't fix it.

 After finding this bug report, and after seeing the behavior improve
 during the day and worsen at night (but never disappear), it occurred to
 me that moisture might be the cause.  So yesterday I opened the keyboard
 up, pealed back the rubber keypad, and let the whole thing "air out".  The
 performance improved immediately after I put it back together.  Although
 the ctrl and alt keys started sticking a little last night, and again this
 morning (I was able to get them to unstick by jiggling them a little), I
 am typing this report on the same machine that was unusable two days ago
 (now running 653 again), and I haven't experienced a stuck key since this
 morning.  I don't know if opening up the keyboard did the trick (maybe the
 benefit is that I undid the seal, which might now provide some vent
 space), but I am unsure as to whether I really need to RMA it anymore (I'm
 going to wait a couple of days).

 There are other reasons to think that this is a physical issue related to
 moisture/condensation, from reading the comments above and in the forums:
  - extremely unpredictable/variable occurrence
  - performance changes over time (improves/gets worse) with no apparent
 cause or change to/interaction with the machine [evaporation/condensation]
  - responds to physical movement of the machine and certain physical
 stresses [movement of the fluid]
  - a key that is next to another key can cause that key to stick/unstick
 [movement of the fluid]
  - pressing a stuck key can unstick the key (and vice-versa), but not
 every time and not the same way every time. [movement of the fluid]
  - the keyboard mechanism functions by completing circuits by pressure,
 but moisture can also complete those circuits (the connectors of which are
 spaced less than a millimeter apart, unlike mechanical keyboards).
  - the keys that are getting affected the most are at the edge of the
 keyboard (alt,ctrl, fn, space) [where moisture is most easily introduced]
  - a sealed, rubberized keyboard might keep moisture in as much as it
 keeps it out.

 I would ask some questions of users with this problem: what is the weather
 like when the sticking gets worse or gets better?  Does it stick more when
 it is humid/raining/foggy or at night?  Does it stick less when it is
 dry/sunny/clear or during the day?  If you try to "dry it out" does that
 help?

 I would ask OLPC: are the new keyboards sealed in a different way than the
 prototype models?  What is the geographical/climactic distribution of
 individuals reporting the key-sticking problem?  Is the environment where
 the malfunctioning machines were built different than where the prototypes
 or functioning machines were build? Where the malfunctioning machines
 built on a rainy/humid day?

-- 
Ticket URL: <http://dev.laptop.org/ticket/5658#comment:31>
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