Wonky PageUp / PageDown Key Operation

November 6, 2008 2:22 PM

The PageUp and PageDown keys on my Dell Inspiron 6000 laptop have started acting weird. Sometimes they act correctly (rarely), sometimes they take me directly to the top or the bottom of the current page (now and then), and sometimes they don't work at all (often). I'm seeing this mostly in Firefox, haven't check other apps yet. This started about a week ago, a few reboots and cold starts since it first occurred...not seeing any improvement or further degradation. Do you know why this is happening, how I can diagnose the issue, and/or how it can be fixed? I use those keys often and this is really hampering my use of my laptop.
posted by Exchequer to Computers & Internet (9 answers total)

Best answer: I don't think that this is a software issue, hence rebooting isn't going to help.

It sounds like your keyboard is failing - it's pretty common, especially with laptop keyboards. I don't know if you can 'pop' the keys off of that kind of laptop, but get some compressed air from your local giga-store and spray around the key in a 360 loop, key up and key partially down. See if that helps.
posted by unixrat at 2:29 PM on November 6, 2008

Response by poster: Air can in hand...will report back shortly...
posted by Exchequer at 2:31 PM on November 6, 2008

Response by poster: 1) Yes, the keycaps from the keyboard of a Dell Inspiron 6000 laptop pop off fairly easily. I pried them off starting from a corner with the blade of a pocketknife, no problem. They snapped back on easily, too.

2) Blowing out the keys appears to have restored the proper function. This surprised me as I'd given the entire keyboard a cursory blowjob (!!!) a few weeks ago. I didn't remove any of the keycaps at that time, so that must've been the magic bullet.

Thanks, unixrat!
posted by Exchequer at 2:56 PM on November 6, 2008

Despite the fact that you seem to have solved the problem... your symptoms could have been the result of having Caret Browsing turned on in Firefox. You can toggle it on and off with the F7 key.
posted by ellenaim at 3:16 PM on November 6, 2008

I don't see how Caret Browsing could be to blame. I think it was definitely a hardware issue. The keys were alternating between getting stuck (which would result in scrolling all the way to the end of the page very quickly) or not working at all.
posted by qvtqht at 3:50 PM on November 6, 2008

Response by poster: When they were malfunctioning, they didn't seem to be getting stuck, they weren't causing a rapid, repeated scroll to the end of the page. They were mostly not doing anything, and sometimes, they were going directly to the end. That part was really throwing me, it was as if their function had CHANGED.

I will check into the Caret Browsing toggle.
posted by Exchequer at 5:24 PM on November 6, 2008

Normally, keys auto-repeat at some reasonable rate (you can see the rate if you hold down a letter key in a text window). Keys with dirty contacts, though, will not generate a nice clean auto-repeat. Instead, they will generate a burst of key-down + key-up events in a very tiny space of time, like maybe a few milliseconds. If you send an application program fifty page-down keystrokes in less time than it takes to redraw its window, it will indeed go straight to the end of the scrolling range without doing intermediate redraws.
posted by flabdablet at 2:48 AM on November 7, 2008

Also, if Page Up and Page Down were next to End and Home, then crud under the keyboard could have had you pressing one key, but affecting another.
posted by the latin mouse at 8:53 AM on November 7, 2008

And sometimes modifier keys (shift, control, alt) can get invisibly stuck in the 'down' position - tapping them repeatedly usually clears up the problem, which may be what you were experiencing.
posted by DandyRandy at 11:56 AM on November 7, 2008