Why is distilled water safer for cleaning parts?

[Rodion15]

On reading a webpage on how to clean a laptop case I read: "use distilled water to clean laptop cases better because normal water contains minerals that may produce short-circuit". Something I don't understand if you're careful not to turn-on the machine if it has minimal dampness. I can imagine engineers shooting to a pharmacy for distilled water and spending precious time just for that. Distilled water conducts electricity as well doesn't it?

 

[Grimwinder]

Because it doesn't leave a mineral residue after it evaporates. It's not the wet state, it's what is left behind after drying. Not an issue in 99% of cases but why take a chance is the engineer's stance.

 

[Someone Somewhere]

Distilled water has no ions (aside from the H3O+ and OH- ions that an extremely small amount of water splits into), and thus cannot conduct electricity.

It also has no other chemicals that will not evaporate cleanly, as above.

High-concentration alcohol (typically propanol to make it a bit less drinkable) is also frequently used, and also helps dissolve many other chemicals that might be coating the board already.

 

[Rodion15]

Great answers. Thanks a lot!