iMac (27-inch, Mid 2010) Symptom Charts — Display 57
2010-09-09
8. Verify if high pitch noise varies
when adjusting brightness level
up and down.
Yes Noise seems to be generated
by vertical sync cable. Inspect
and replace cable. Replace
the LED Backlight board if
problem persists.
X03
No Noise is from another source.
Go to step 8.
9. 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 9.
M04
No Noises that are not audible
from the normal user position
are considered acceptable.
10. Verify if noise is still present. Yes If noise still present, go
to Noise/Hum/Vibration
symptom ow.
No Issue resolved.