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51046
August 31st, 2013 08:00
Randomly repeating keys Latitude E6520
One in a while (eveyr few hours) my laptop internal keyboard randomly starts "typing" a key. This can be stopped by pressing another key. Perhaps the problem is triggered by accidentally hitting two keys at once. It is difficult to reproduce the error, but it occurs typically several times per day.
The problem has been present from the very beginning when I bought the laptop from Dell.I recently tried reseating the keyboard cable and then replaced the keyboard by a new one after calling technical support. The problem is still there.
The installed operating system is linux fedora. The problem occurs in all fedora versions I have ever tested (from 16 to 18; different kernels). I have used the same operating systems on other laptops (Acer) and never experienced this problem.
I have used the lattitude with an external keyboard for a couple of hours at a time, though not very often. I have never seen the problem with an external keyboard. I ran the diagostic utility in the bios, but no problems are reported.
Does anybody have any ideas on possible causes, or on possible additional tests? Note that I cannot run or install windows or ubuntu on this laptop. The dell utility partition is still there, although I cannot seem to boot from it ("cannot load kernel image" or a similar message).
Olivier Berger
1 Message
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September 23rd, 2014 06:00
Would this by any chance be what is reported in this forum : http://en.community.dell.com/support-forums/laptop/f/3518/p/19593360/20679876# ?
wphilips123
2 Posts
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September 27th, 2014 09:00
The keyboard symptoms are indeed the same (I do not have backlight issues).
The problem is definitely specific to some dell hardware. I have many laptops and computers running the same operating system and none of those has/had those problems.
The problem is due to a combination of two factors
-something specific about the keyboard-related hardware in this laptop generates keypress/release
events that are unusual (compared to other hardware) in some way (order of keypress/release events and timing)
-some bug in Xorg reacts badly to this unusual problem
I seem to remember that the issue is that keypress/release events occur in an unusual order:
something like : key-press-H key-press-J key-release-H key-release-J. It is probably more complex than that. I guess timing plays a role.
The problem is quite annoying. It does not occur on a the dell XPS I bought more recently.
In my experience the dell hardware is usually quite nice, but it always has one specific problem that seems impossible to fix. In the Dell laptops I bought I experienced:
-continuously running fans
-auto-disconnecting ethernet
-the keyboard issue
-the touchpad issue.
In addition, you have to be very careful when you order, because offers in the context of a framework agreement are too often more expensive than what you can find on the web.