4/5 kobos? What did happen to them? I suspect the screen broke after a fall. Happened to the one of my sister. In that case try to use an harder cover because 4/5 are a lot
Yeah, some were dropped, but not from great heights or anything - normal wear and tear that a regular smartphone would easily survive. She does have covers for them. I think one even had like a 1' fall onto carpeted stairs and then wouldn't turn on anymore.
I think her latest one has lasted a lot longer though, so maybe they've steadily become more sturdy...