My Mac Mini from 2007 always stayed connected to my home network. No problems. (Wired, NOT wireless.)
All this week it becomes disconnected at random times. Nothing can re-connect it... until I remove the Ethernet cable... and reconnect it. (At the router.)
Happens randomly... every 2-10 hours of use.
How would you diagnose something like that? (I have a thousands of hours of PC experience. But know very little about the Mac.)
(OS 10.6 with all the latest updates applied)