Saturday, April 28, 2012

Laptop with unknown stuck key

I was asked to work on this laptop to address a slowness problem, a Dell Inspiron 1501. I booted it up and first noticed that a disk check was scheduled. It would go to that point where it said press any key to cancel the disk check, and then it cancelled itself out. It was as if I had pressed a key, but I wasn't pressing anything.

This obviously struck me as odd. My impression was that a keyboard key was stuck, but I could not find any keys that appeared depressed at all. So I continued on, as there was nothing else I could do just yet.

I was going to connect it up to my Wi-Fi, in case I needed to do anything online. So I brought up the window to configure the connection, hit caps lock and saw the expected balloon notification that caps lock was on. But I noticed that the balloon was disappearing within a second or so, it was just "blinking out" by itself. Again, I'm thinking stuck key, but which one?

I couldn't find any keys that seemed stuck, and there was no unexpected text output. Still, my sense was that a key was in fact stuck, but I was hard pressed to determine which one. I pulled up Windows On Screen Keyboard (osk.exe) to see if it would show me any active keys, but that revealed nothing. I also tried mashing across all the keys on the keyboard. All that accomplished was to open a bunch of random programs and activate several Accessibility features. I shoulda done that with the computer off :\

I started to think that either the keyboard was on the fritz, or perhaps something spilled on it causing one or more keys to behave as if stuck. But the latter seemed pretty unlikely to me, so I dismissed the idea.

I plugged in a USB keyboard, and was planning to disable the built-in keyboard via the Device Manager, but no can do. Apparently, one is not allowed to disable this device. I tried uninstalling, but that required a reboot, and that just led back to Windows re-detecting and reinstalling the device automatically. Poop.

I did some Googling and came across various ideas, one of which caught my attention. The suggestion started with updating to the latest BIOS version, but it already was. Next was to unplug, remove the battery, and hold the power button for 3 seconds, three times. This is similar to what I've always known as a "static dump," but I'd never have thought it could solve this type of problem. I did it anyway, and was pleased with the result. However, I only held the power button once for 10 seconds. I don't know about that three times thing, seems hokey. Interestingly enough, the forum post I found happened to be regarding the same make and model of laptop. Go figure.

Whatever was going on with the stuck key syndrome was causing other weirdness too, which I didn't realize until after it was fixed. For instance, the mouse keys on the touchpad seemed less than responsive. I'd have to either press them multiple times, or press them more firmly, before I saw a result on-screen. Also, the tap-to-click feature of the touchpad was not enabled, but I like the feature so I enabled it. I found that this too was behaving similarly, working but requiring several taps to get it to register. I was prepared to chalk this up to parts wearing out on an aging laptop. Clearly, that was wrong.

Before I got that solved, I was going to start addressing the slowness issue with a defrag, but since the disk check was scheduled, the defrag wouldn't run. I felt much more confident that the stuck key issue was fixed when the disk check actually ran and completed. Then, I did the defrag, yay.

The system is running better now, I'm sure due in part to the defrag and my other routine maintenance tasks, but I think also it feels snappier because the touchpad is more responsive now. Such an obscure problem with an odd fix. Who'd a thunk it?

In the end, the fix for the "phantom" stuck key was to unplug the laptop, remove the battery, and press and hold the power button for 10 seconds.

Here is the forum post that inspired me. Thanks, Dracia.