Справочник Пользователя для Apple MD094LL/A

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

 2010-09-09

4.  Pivot enclosure to access 

lower intake vent, and locate 

 on edge of 

logic board. Verify if LED #3 

turns on shortly after system 

powers on.

Yes

Logic board communicating 

with video card. Go to step 5.

No

If LED #3 does not turn ON 

reseat video card and retest, 

then replace video card and 

repeat step 4. If issue persists, 

replace logic board.

5.  Locate 

 on 

logic board. Verify if LED #4 

turns on shortly after system 

powers on.

Yes

Logic board communicating 

with LCD panel. Go to 

symptom flow.

No

Replace DisplayPort cable. Go 

to step 6.

6.  Locate 

 on 

the logic board. Verify if LED #4 

turns on shortly after system 

powers on.

Yes

Video controller functional 

and communicating with LCD 

panel. Go to 

 symptom flow.

No

Video controller unable to 

communicate with LCD panel. 

Reseat cables first. If issue 

persists, replace LCD panel. 

Retest.