iMac (27-inch, Mid 2010) Symptom Charts — Communications 90
2010-09-09
Ethernet Port/Device Issue
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
Ethernet Port/Device Issue
• No Ethernet device present
• Unable to access network
resources
• Ethernet device shows no
connection
• Ethernet device unable to an IP
address
• Slow network performance
1. Check Ethernet cable for damage. Try a
known good Ethernet cable – CAT5 or better
recommended for 100Mbps+ connections.
2. Check Ethernet ports on the computer and wall/
switch for dust, debris, damage or bent pins.
3. Ensure distance from networking infrastructure is
less than 300 feet/ 105 meters.
4. Verify port, cable and network hardware with a
known good system. Isolate rewall, MAC address
ltering or hardware access control devices.
5. Isolate OS by starting up from original Install
media for this computer, a same-model computer
in Target Disk Mode, or compatible known-good
OS on an external drive.
Deep Dive
Check Result Action Code
1. Visually inspect Ethernet port
of computer and ensure that all
pins will make physical contact
with the Ethernet cable.
Yes Go to step 2.
No Pins are damaged, bent at or
missing. Replace logic board.
M24
2. Boot from original Install media.
Verify Network Link status is
active by using Network Utility
under the “Info” tab. Verify if the
Link Status is “Active”.
Yes Go to step 3.
No If same Ethernet cable gives
an “Active” link status on a
known-good, same-model
computer, replace logic board.
M10
3. Connect computer to another
Mac using CAT5 Ethernet
cable. See article http://
docs.info.apple.com/article.
html?path=Mac/10.6/en/8429.
html. Verify if you connect
successfully.
Yes Ethernet communication
good. Go to step 4.
No If same Ethernet cable and
computer connects to a
known-good, same-model
computer, replace logic board.
M10