More like WRONG arrow key, amirite?

October 25, 2008 7:52 PM

My laptop's right-arrow key is remapping itself. Any tips for diagnosis or repair?

The right-arrow key on my laptop is behaving badly. It seems to be wildly remapping itself several times per second, varying between a few keys. After a little testing, here's what I found out:

- Inside a text field, pressing it will produce either "n/ " or "b". It varies between the two randomly with repeated keypresses. Example:

n/ bbbn/ n/ / bn/ / n/ n/ bn/

(Yes, I realize it typed "/" twice in the middle there -- no clue why)

- When it does type "b", it also minimizes whatever application I'm using.
- When testing in Notepad, pressing the arrow also displays the little underscores under "File", "Edit", etc. that usually appear when you press "Alt", suggesting this key is getting selected, too.
- To see exactly how the key was working, I brought up a driving game that has an area in the menu to test the controls -- pressing the acceleration key will fill up a bar slowly to the maximum speed, for instance. I mapped this function to the arrow, then pressed it. Instead of filling the bar smoothly, it caused it to jitter around a bit but never increase, as if I was lightly tapping the key over and over again.
- Lastly, and most puzzling: the problem comes and goes, seemingly not tied to any one program or process. It'll be there when I boot up, disappear for awhile, then return for no visible reason.

I thought the problem was rooted in a Windows Update I had recently added that XP had been nagging me to install, but rolling back to the pre-Update (and pre-problem) state via System Restore didn't fix it. Rebooting does nothing, either. And I don't have any spyware or viruses, to my knowledge -- my AV software hasn't given me any warnings lately.

My laptop is a Dell Latitude D820, running Windows XP SP2.

Any thoughts? Are there any Microsoft diagnostic tools I could run to repair this irritating little problem?

posted by Rhaomi to computers & internet (10 comments total)

Any water hit the keyboard lately? It might be worth hitting it with a hair dryer (no heat!) and see if it's a little short in the membrane under the keys.
posted by jenkinsEar at 7:57 PM on October 25, 2008

Not that I know of, jenkins. I know there's a way to remove the keyboard tray to clean out the underside, so I'll try that soon.

Also, I discovered that the Windows shortcut for minimizing a window is Alt+space -- both which appear when I press the arrow. So there goes that mystery...
posted by Rhaomi at 8:02 PM on October 25, 2008

(jenkinsEar, I mean)
posted by Rhaomi at 8:02 PM on October 25, 2008

Okay, scratch the Alt+space thing, that just brings up the little corner menu -- you still have to arrow down to the "Minimize" option to get it to work.
posted by Rhaomi at 8:05 PM on October 25, 2008

Can you see if it happens in the BIOS, or, if not there, then when booting from a linux livecd or something similar? This sounds to me very much like a hardware problem, and doing that would eliminate any possibility of a software bug.
posted by alexei at 10:51 PM on October 25, 2008

Alexei, unfortunately (?) I can't test it right now as the problem has vanished once again. I had tried earlier to clean the keyboard -- there didn't appear to be any wetness or obstructions, although it was difficult to tell. I'll give your BIOS tip a try if and when the weirdness resurfaces.
posted by Rhaomi at 11:27 PM on October 25, 2008

Why futz around with it for the $15 cost of a replacement? I used to change Dell Inspiron keyboards all the time. It's easy and cheap, even for yours.
posted by rhizome at 12:39 AM on October 26, 2008

Why not try getting a remapping program like Auto Hotkey, remap your arrow key, and see if it still changes itself?
posted by theichibun at 6:08 AM on October 26, 2008

I had a very curious keyboard remapping problem after dropping a drink on my keyboard. It came and went, as yours is, though when the mapping was bad, it was much worse than what you describe. The bad mapping even affected a USB keyboard, sometimes lasted through several reboots, and could spontaneously occur even when the laptop keyboard was disconnected!

Keyboard replacement fixed it completely! And as rhizome says, cheap and easy to do.
posted by Chuckles at 7:33 PM on October 26, 2008

Your alt + space theory is still valid, because the keystrokes for Minimise are alt + space + n.

Also, plug in a USB keyboard, and see if THAT arrow key does the same thing. If it doesn't, continue using the USB keyboard (or replace the laptop's keyboard).
posted by exphysicist345 at 7:31 PM on October 27, 2008