Apple 2009 iMac - Page 46

iMac (21.5-inch, Late 2009) Symptom Charts — Display 46
2010-11-18
5. Shine bright (low heat)
ashlight into front of LCD.
Verify if an image is being
displayed when ickering issue
is occurring.
Yes Image present but backlight
is ickering. Replace vertical
sync cable (between LCD
panel and upper end of LED
backlight board) and retest.
If issue persists, replace LED
backlight board.
X03
M04
No Replace LVDS cable between
LCD panel and logic board,
and retest.
X03
6. Verify if noise varies when
adjusting brightness level up
and down.
Yes Noise seems to be generated
by vertical sync cable. Inspect
and replace.
No Noise is from another source.
Go to step 7.
7. Verify if noise can be heard
when computer is set up with
user seated in normal user
position. Adjusting brightness
level up and down may be
necessary to recreate issue.
Yes Replace LED backlight board.
Go to step 8.
M04
No Noises that are not audible
from the normal user position
are considered acceptable.
8. Verify if noise is still present. Yes Replace LCD panel. If noise
still present, go to Noise/
Hum/Vibration symptom
ow.
L06
No Issue resolved.