[JasonACT]

These devices (a small computer) rarely ever re-boot.. A lot of the software on them is loaded into RAM (which is very stable) where it runs for years. That is, until you spike the power (jump-start) or disconnect/reconnect the battery. The Flash memory chip itself (where all the files are loaded from, at boot time) has a 10 year "estimated life" but it goes bad in the heat much quicker. Bad files do get corrected by special software and extra bits on the chips, but if they get too bad, even that fails and the units can fail to boot properly - which means "blank screen" / "lines down the screen" / "stuck on the boot splash screen". Depends on which files and how far into the boot cycle it gets before it stops.

Image files are often reloaded as they are not kept in RAM all the time - so sometimes you can see corruptions in images on these screens without rebooting.