Apple MD094LL/A Manuale Utente

iMac (27-inch, Mid 2010) Symptom Charts — Startup and Power 

 2010-09-09

Unlikely cause: hard drive, optical drive, speakers, camera, microphone

No Video
•  No image.
•  Backlight failure.

1.  Check brightness setting.
2.  For no-video issues, connect an external display 

to Verify if iMac video circuitry is functioning. 

If image appears on external display go to 

Backlight Issue/No Backlight symptom flow.

3.  Reset SMC.

1.  Verify boot chime present and 

fans running when system 

powered ON. (Reset SMC, clear 

PRAM or reseat Backup Battery 

if necessary for proper boot 

up.)

Yes

Power ON self test OK. Boot 

sequence started. 

Go to step 2.

No

Go to 

 

symptom flow.

2.  Verify if image is visible on 

built-in LCD panel.

Yes

Video present. Verify system 

functionality and return to 

user or jump to appropriate 

troubleshooting flow.

No

Go to step 3.

3.  Connect supported external 

display. Verify if image appears 

on external display when 

system is booted.

Yes

External display detected by 

system. Video circuitry on 

logic board functional.  

Inspect DisplayPort cable to 

back of panel connection. 

Reseat and test again. If you 

continue to have problems 

go to 

 symptom flow.

No

Go to step 4.