I dissembled my device to replace a HDD with a new SSD. When I put everything back, all the components worked flawlessly. However, when it go to sleep mode, the backlight not turn back on, I still can see the content on display if I shine the flashlight on it. Every time I want to get backlight back on, I had to unplug the device and leave it there for a while, then plug it back and turn on.