Apple MD094LL/A Manuale Utente

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

 2010-09-09

Respond
•  One or more keys do not 

respond when pressed

•  Key sticks
•  Keycap missing

1.  If wireless keyboard is being used verify that it is 

properly paired with computer. Go to 

 symptom flow to 

resolve pairing issues.

2.  The caps lock key has a built-in delay to reduce 

accidental activation and must be held for 

approximately ½ second for it to be activated. See 

.

3.  Inspect keyboard for signs of liquid spills or other 

contamination. Apple’s warranty does not cover 

accidental damage.

4.  If keycap is loose attempt to reattach it.
5.  Use the Keyboard Viewer menu to check every 

key.

6.  Recheck keyboard with a known-good computer 

with an up-to-date Mac OS X 10.6.x

7.  Replace keyboard if issue is confirmed (K01 for 

inoperative keys, K17 for wrong/falling keycaps).

Recognized
•  USB wired keyboard/mouse not 

recognized when plugged in.

•  Mouse scroll ball not working 

or not working as expected.

•  Mouse buttons not working or 

not working as expected.

1.  Reset SMC.
2.  The iMac has 4 USB ports on rear of computer. 

Make sure to try each port to isolate a particular 

port malfunction.

3.  Test with a known-good wired keyboard or 

mouse to isolate a failed peripheral issue.

4.  Test a mouse when connected directly to ports 

on the back of iMac to isolate a keyboard USB 

port issue.

5.  Ensure that all software and firmware updates for 

this model have been installed to take advantage 

of any available bug fixes.