My Linea Mini is not that old (less than a year) and I started having issues with the paddle. When moving the paddle from right to left (engaging), it would sometimes not respond. After doing the motion multiple times, it would eventually trigger. I thought this was a software issue.
One morning, it stopped altogether. No matter how many times I moved the paddle, turned off/on the machine, it just wasn't responding. At this point, I was thinking it could be the paddle's internal switch. I removed the top cover and saw what appeared to be a cheap plastic switch. My suspicions grew. After engaging the paddle, I pushed on the metal tab of the switch further and heard a click, confirming the paddle wasn't fully engaging the switch. I didn't see any easy adjustment to the switch to where I could move it closer to the paddle, so I carefully put a bend (u-shaped) in the middle of the tab so there was less gap between the switch and the paddle. A few quick tests while the cover was off confirmed the switch was now fully engaging.
This was an easy but annoying fix. I figured for the cost of the machine, a higher quality switch would be used and would have proper adjustment. I'm documenting this experience for anybody else that runs into a similiar issue. Perhaps the fix for you is just as easy!
