iMac (27-inch, Mid 2010) Symptom Charts — Startup and Power 47
2010-09-09
4. Pivot enclosure to access
lower intake vent, and locate
diagnostic LEDs 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.
M03
M03
5. Locate diagnostic LEDs on
logic board. Verify if LED #4
turns on shortly after system
powers on.
Yes Logic board communicating
with LCD panel. Go to
Backlight Issue/No Backlight
symptom ow.
No Replace DisplayPort cable. Go
to step 6.
X03
6. Locate diagnostic LEDs 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 Backlight Issue/
No Backlight symptom ow.
No Video controller unable to
communicate with LCD panel.
Reseat cables rst. If issue
persists, replace LCD panel.
Retest.
L03