Several weeks ago my USB controller stopped working: it's "seen" system - for I can see hub 1-0:1.0: USB hub found hub 1-0:1.0: 4 ports detected in /var/log/dmesg yet it does not function - for it reflects not on plugging a device in. Then I bought a separate controller - and it works now just fine. But! Today I needed my built-in network card to connect to another machine - and I was not able to make it working... I compiled all the drivers for it (10Mbit-1000Mbit - and I have 1Gbit one) but the device like /dev/eth0 didn't appear although I see eth0: Yukon Gigabit Ethernet 10/100/1000Base-T Adapter PrefPort:A RlmtMode:Check Link State in /var/log/dmesg. But I suppose it can be the same case like with built-in USB controller: the device is seen but does not function... So, my question is: how I can check my hardware? Including that bad USB controller as a test for that checker?! - Thank You. -- Best regards, Strong.