^[[2~ characters r printed continuously during boot time & after booting [closed]

Question

I'm using ubuntu 18.0. During boot time and after there are getting characters like this printed contiguously:

^[[2~  ^[[2~  ^[[2~ ^[[2~ ^[[2~ ^[[2~ ^[[2~^[[2~

Particularly these symbols are stopping my work when i'm using Terminal, Gedit etc., I'm using Lenovo laptop. I checked with ubuntu 14, ubuntu 16. Same behaviour is observed.

print screens of error message.

Kindly help me in fixing this issue.

Answer 1

In a nutshell, a stuck function key or background program? is send a control code to your terminal that it does not understand (not all terminals types can understand all escape sequences) so it gets printed literally. ^[ is the start of an escape command sequence, like pressing the ESC key. These can be used to turn on and off bold text for example. The command is [2~. This appears to be a "Control Sequence Introducer" according to WikiPedia: https://en.wikipedia.org/wiki/ANSI_escape_code#Escape_sequences but who knows what the actual command actually is.

Since it's happening with different versions of an OS I suspect a hardware problem as it seems other letters are randomly missing too. If you have the skills and comfort level to remove the keyboard (hopefully it's easily on your laptop) you could try removing it, turning it upside-down over a trash can and give it a good shaking. At the least, blow it out with a can of compressed air. Do at your own risk!