Apple MD094LL/A Manuale Utente

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

 2010-09-09

Unlikely cause: LCD display, power supply, hard drive, optical drive, fans

USB Device Not Recognized
•  USB wired keyboard/mouse not 

recognized

•  USB external drive not 

recognized

•  USB camera not recognized
•  USB printer not recognized

1.  Reset SMC.
2.  For printers and external USB drives, make sure 

any external power source is plugged in and 

operating to isolate a power issue with device.

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

each port to isolate a particular port malfunction.

4.  Test with a known-good wired keyboard or 

mouse to isolate a failed peripheral issue.

5.  Test with a known-good USB cable when dealing 

with a printer or external USB drive, to isolate a 

USB cable issue.

6.  Ensure that all software and firmware updates for 

this model have been installed to take advantage 

of any available bug fixes.

7.  Launch Apple System Profiler and verify if device 

is visible on USB bus. If yes, then the USB port and 

cable are functioning properly. Contact device 

manufacturer to verify that device is supported.

1.  Unplug all USB devices from 

the computer except for USB 

keyboard and mouse. Start 

computer and reset PRAM. 

Verify if USB keyboard and 

mouse are recognized.

Yes

Test with all USB ports to 

ensure all USB ports working 

as expected. Replace logic 

board for any port failures.

No

Reset SMC. Go to step 2.

2.  Verify if Bluetooth Mouse Setup 

assistant launches after startup.

Yes

Bluetooth detected, but 

external USB devices not 

recognized. Go to step 3.

No

Disconnect USB keyboard and 

mouse. Go to step 4.