iMac (27-inch, Mid 2010) — General Troubleshooting 33

2010-09-09

Functional Overview

Refer to this diagram for symptoms related to logic board connectors. To rotate this page in Preview for easier

viewing, go to Tools menu and choose “Rotate Left”.

CPU Fan:
- system freezes or kernel panic if
CPU gets over heating
-reduced performance or system
sleep if CPU temperature gets
too high due to disconnnected
blocked fan
Bluetooth :
- cannot enable
Bluetooth
Hard Drive Temperature
Sensor:
- fan running at higher
speed if sensor cable is
dis/misconnected, or not
matching drive brand/
model
Hard Drive Fan:
-hard drive data
corruption if HD
fan is blocked or
disconnected
Optical Drive Fan:
-ODD temperature
getting too high
-media read / burning
fails if fan
disconnected or
blocked
Power On Button:
- no Power On (unless shorting the
pads on logic board) Microphone:
- no internal microphone input
Optical Drive Temperature Sensor:
-ODD fan running at higher speed
-media read/burning fail if ODD
temperature gets too high
CPU Temperature Sensor:
- fan running at higher speed,
- reduced performance or system
sleep if CPU temperature gets too
high
IR Receiver:
- no IR Remote functionality
SD Card Reader:
-no SD card reader seen in System
Profiler/ USB
-no SD card read/write
Power Supply + Backlight Control +
Power Supply Temp sensor:
-no Power, no Video
-no/poor backlight control,
-fan running at higher speed
- reduced performance or system sleep if
power supply temperature gets too high
Camera + Camera
LED :
-no camera
functionality
-no camera LED
when camera is on
Skin (Enclosure)Temperature
Sensor:
- fan running at higher speed
- reduced performance or system
sleep if enclosure temperature gets
too high
LCD Temperature Sensor:
- fan running at higher speed
- reduced performance or system sleep
if LCD temperature gets too high
AirPort Card:
- cannot enable AirPort
DisplayPort LCD :
- poor / no video on internal LCD
MXM Video Card:
- no video on internal LCD and on
external DisplayPort connector
Video Card Temperature Sensor:
- fan running at higher speed
-video artifacts / video freezes
- reduced performance or system sleep
if video card temperature gets too high
Left Speaker :
- no sound from left
speaker
- distorted left
sound
Right Speaker
- no sound from
right speaker
- distorted right
sound
Ram:
- no boot,
-beep tones on startup,
-freezes, or kernel panics
Analog/Optical Audio In/Out:
-no Analog/Optical audio input/output
-only Optical Ports seen in prefs
Ambient Temperature
Sensor:
-fan running at higher speed
- reduced performance or
system sleep if temperature
gets too high
Hard Drive (and SSD) SATA data:
- no boot from bootable HD (or SSD)
-no HD (or SSD) visible on SATA bus
-Optical Drive SATA data+ Power:
- no boot from ODD drive
-no ODD seen on SATA bus
- ODD drive does not inject /eject any media
Backup Battery:
-no video
-beep sequence on startup