I purchased a refurb Quickfire TK and used it without issue for several months with multiple machines, running variously Windows 10, Linux and macOS. Then rather suddenly, the keyboard stopped working on my primary MacBook, with several important keys like Tab, Space and Backspace no longer registering, and other keys sending extra signals (e.g. the 'd' key adds a tab (\t) after 'd' every time I press it). If I remember correctly, the problem came up while I was actively typing, with a dialog popping up asking me to identify the now-unknown keyboard (which always concludes as an ANSI United States 101/102). I've reproduced this at this point across three MacBooks, whether directly connected or via a USB hub.
This issue has persisted for months. I would have long ago just ditched the keyboard, but the strange part of this is that it still operates flawlessly on my Thinkpad, whether I'm connected directly or via a USB hub, in Windows 10 and Linux. I can't find any similar experiences in these forums or in several google searches specific to Quickfire or generally about external keyboards.
I attempted to fix my problem by following all of the steps recommended in macOS Sierra: If keys on your keyboard don’t work. The only progress I made there was finding the keyboard viewer, which helps corroborate all of the errors I'm seeing. I also tried some different keyboard layouts, but that didn't solve the problem.
My specific errors:
arrow keys: dead
When I change the keyboard layout (e.g. to Dvorak), the same physical keys are dead, and the same physical keys pass extra events to the operating system. For example, in Dvorak the third key to the right of the tab is '.' instead of 'e'. When I press it, I get ". " on whatever document I am editing.
Any ideas? For example, is there any recommended physical maintenance that I can perform? I really love this keyboard, but have to use macOS for work; would be sad to have to replace it.