I purchased a Lenovo Flex 3 for my Freshman year of college, and it broke during my first semester, right before finals. The keyboard entirely stopped working, none of the USB ports worked, I have no idea what happened. Even before then, it would give me the blue screen of death and reboot at random. I contacted Lenovo support, and they said if I shipped in my laptop, they could fix it and send it back to me. I told them this was fine, but they only had a month since I needed a computer for the spring semester.
Weeks passed, and they made no progress on fixing my laptop, so they sent me a new one. I received a Lenovo Flex 4, since they stopped making the Flex 3. I thought that would be the end of it. Unfortunately, about 8 months later, the Flex 4 died in a very similar fashion. Lenovo could not do anything about it since I was past the 1-year warranty of my original laptop. When I took it into a shop, they said it was a motherboard problem. Replacing the motherboard would have been more expensive than getting a new laptop, so I got a new laptop.
I will never invest in another Lenovo product. Not only are their products unreliable, their customer service is as well.