1

I am using a Dell laptop with Windows and Ubuntu 18 dual-boot. Recently I have an annoying problem with my laptop, ghost keypresses. If I'm reading an article or a long mail or reading a PDF file, the page will scroll down automatically after 10-15 seconds of idle.
The problem is there on Ubuntu in both Chrome and Firefox. The issue is probably caused by an automatic keypress triggered by the presence of dust. However, I could not identify which key is being triggered.
We have several possible keys,

  1. The four arrow keys ( ) on the keyboard
  2. The tiny joystick on the keyboard ( the small button between G, H and B keys )
  3. The trackpad
  4. The buttons of the trackpad

How can I find what is causing this? and how to fix this?

1

I would load ubuntu and start showkey and let it sit for a while examining the output. That will give you the scancodes of the key that is being triggered.

However, this will not trigger if it is the trackpad. I don't know if something like this answer might help there? The essence is to start a program that will show you the raw output (or as close as possible) from your peripheral (touchpad/trackpoint) so you can detect whether any input is received without you doing anything

2

You've got an answer on how to find out the keys causing problems, now for the solution:

Good hard cleaning!

(If not under warranty, opening warrantied notebook might void the warranty)

If the notebook is still under warranty and you don't want to loose it you might want to send it to authorized service after backing up the data and removing any compromising and sensitive materials

I have seen similar problems with laptops used by people who eat while using them (fries are surprisingly sticky and the oil congeals after some time) or when a lemonade or other fizzy soft drink spilled into the notebooks.

I'm only using eating as an example, the same effect can be achieved with dusty environments (main cause) or storage (your bag might contain more lint and dust than you think) and that combined with water condensing in your electronics when rapidly transferring indoors-outdors can help to get contacts "stuck". So, proper cleanup of the insides is my recommendation once every few years...

It's not the end of the world and unless the keyboard is backlit - and probably even then - the cleaning should be possible and not that hard.

If your laptop is even remotely current (15 years or younger), there ought to exist a youtube disassembly video. Use it with a liberal application of vacuum or canned gas or compressor to clean up the dust and take out the keyboard desk, which you can then clean up with detergents and water and let properly dry up. You can even take out the keys if you're careful and adventurous, but a detergent and a painting brush to get under the keys from the side was usually sufficient for me.

Be careful of some laptops, which may require removing the cooling circuit from the processor/graphics, you're going to need to clean the old paste with alcohol and buy a new one and apply a dollop, but generally, it shan't be needed. If you watch the video, you should find out from that.

P.S.: and check if you don't have an old wireless/Bluetooth keyboard/mouse still connected. I once tried to diagnose this precise problem, where every time I was at home this happened and only found out when I was at my wit's end readying for disassembly I had a dongle from an old wireless keyboard lying under papers pressing some keys in my drawer connected to the notebook. :)

P.P.S.: any kind soul wanting to format the answer better, add more details or warn on using a vacuum to clean electronics (15 years and counting without a hitch) is welcome, I'm writing from my phone and it's a nightmare. I'm making it community wiki.

4
  • Hi, Thank you for your advice. But, I'm not the person who would eat while using the laptop. Rather I'm the kind of person who gets annoyed even by the slightest spec of dust on my laptop or phone. In short, I keep my gadgets super clean and neat. It's unfortunate this happened to me despite all the care and effort. I have friends using the same kind of laptop and their laptop is covered in dust and dirt. But they are working fine. – brownfox May 3 at 8:58
  • @brownfox I was only using oil and eating as an example, the same effect can be achieved by dusty environments and environments with "oily dust" or "humid dust" or large temperature swings condensing water in the deposited dust and everywhere else. For example, the last laptop I cleaned out was perfectly clean from the outside, but repeated storage in a dusty bag and usage in dusty environment had done it's job on everywhere the otherwise properly cleaning owner had not reached or did not think to look at. Hope you solve your problem :) – mishan May 3 at 12:01
  • I understand your suggestion, I'm just pointing out that I never let my laptop expose to dust. BTW I have tried the suggestions of accepted answer and both the keyboard and the trackpad and the joystick are working fine. They are not creating any ghost inputs. – brownfox May 3 at 12:41
  • @brownfox My suggestion is rendered moot by this revelation too, then. – mishan May 3 at 12:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.