Apple MD094LL/A Manuale Utente

iMac (27-inch, Mid 2010) Symptom Charts — Input/Output Devices 

 2010-09-09

Function Properly
•  Some or all keys on the 

keyboard don’t work

•  Eject key or Caps Lock key 

doesn’t seem to work

•  Some keys don’t work as 

expected

1.  Reset SMC
2.  Open System Preferences > Universal Access > 

Mouse & Trackpad and verify that Mouse Keys 

is turned OFF. When enabled, Mouse Keys can 

disable functionality of some or most keys, 

depending on keyboard used.

3.  The iMac has 4 USB ports on rear of computer. 

Make sure to try each port to isolate a particular 

port malfunction.

4.  Test with a known-good wired keyboard to 

isolate a failed peripheral issue.

5.  Test wired keyboard on a known-good, same-

model computer. If it works on the other 

computer, this may indicate a bad USB port if 

keyboard doesn’t work at all on user’s computer, 

or a software issue if keyboard is working but not 

as expected on user’s computer.

6.  Ensure that all software and firmware updates for 

this model have been installed to take advantage 

of any available bug fixes.

1.  Verify if all keys on keyboard 

work.

Yes

Go to step 2.

No

Go to 

symptom flow.

2.  Verify if Caps Lock is working as 

expected.

Yes

Go to step 3.

No

Go to 

symptom flow

3.  Verify if media Eject key is 

working as expected. Note that 

to prevent accidentally ejecting 

media, Mac OS X adds a slight 

delay to the media Eject key 

before it takes effect.

Yes

Go to step 4.

No

Go to step 5.