Why diagnostics are important:

Helldesk: User reports network connection fault at multiple desks. Please check desks.
Me: Hey user please come visit us so we can check your laptop.
User: Laptop keeps losing network when I return from break
Me: Logs say that it's going into standby mode; looks like it's not plugged into power.
User: The laptop overheats when it is.
Me: *checks device* The fan is dead and that's why it's overheating.