I have learned a valuable lesson as of late. Perhaps the most fragile component in a laptop — while it is off anyway is the screen backlight. The way I know this of course is because I have recently killed 2 or 3 on the same laptop. Coincidence? I think not. I may be too rough but I do my best to be careful and never had this problem with other laptops.
What I think is happening is that my laptop case has wheels and if I roll it on rough pavement or pavement with many rocks, the light is dead the next time I turn it on.
Unfortunately this is the sort of test you prefer to do with a laptop you don’t rely on every day.
Still I hope I help others who may have experienced a similar problem. Be very careful. For the record my laptop is an IBM T42p. Other than the excessive returns to the factory for repairs I do love this laptop. I have always had great luck with IBMs but I wonder if it is time for a Panasonic Toughbook.