Weird hardware: how to check it?!

[Strong]

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.