Recently I upgraded to Big Sur on my MacBook Air (13 inch, early 2015 model) and it worked fine for a couple of days. Suddenly the left Shift key shows some random behaviour. Sometimes, it is always on leading to Safe Boot. Some times it is disabled. This behaviour appears randomly and creates a lot of trouble. I checked Internet and tried a few suggestions like installing keymap applications, removing the shift key physically etc. Nothing gave a permanent solutions. Then I removed MacOS completely and installed Ubuntu 18.04 LTS and all keys including the SHIFT key worked perfectly. Which implied that there is no hardware issue with the key. I again installed MacOS (Big Sur) and now the issue (the random behaviour) is back. Is it due to some virus attack? Any solutions?

As per Tetsujin's suggestion I installed Key Codes. The left Shift key didn't give any response. The right Shift key response is shown in the figure attached.

enter image description here

  • 1
    The OS isn't running at the point you enter into a safe mode boot - you're pretty much running from 'ROM' at that point, so my money is on the keyboard. – Tetsujin Dec 3 '20 at 17:04
  • @Tetsujin Yes I also doubted that. But when I installed Ubuntu 18.04, as discussed in the post, everything worked as normal! So I don't think it is a hardware issue. After installing the Big Sur teh last time it went to safe boot only once. – Soo Dec 3 '20 at 17:12
  • Sure, but it's really hard to prove a negative, so you have to sometimes go with your 'gut feel'… & mine says keyboard. Try running Key Codes (freeware) & see if you can see anything suspect – Tetsujin Dec 3 '20 at 17:15
  • @Tetsujin I installed Key Codes as you suggested. But the left Shift key doesn't show any response. However, if I use mouse to select some text in a page, it is showing the behaviour as if Shift key is pressed and holding! Similarly if I click on a new link, a new window opens (as if I pressed Shift key and clicked the mouse)! – Soo Dec 3 '20 at 17:25
  • That would reinforce my opinion that the key is busted, I'm afraid. Hard to make it work could be cleanable/fixable, hard to make it stop working is usually a new keyboard. You could try cleaning it up, but don't expect miracles. – Tetsujin Dec 3 '20 at 17:29

You must log in to answer this question.

Browse other questions tagged .