Apple imac 20 inch early 2008 User Manual

iMac (20-inch Early 2008)  — Symptom Charts  2 51
The computer won’t burn discs
Check whether the drive can read CDs and DVDs normally. Perform the steps above for “CDs 1. 
or DVDs don’t show up on the Desktop.”
Try a test burn by creating a Burn Folder, as follows.  
2. 
• In the Finder, choose “New Burn Folder” from the File menu.  
 
• Open the Burn Folder, drag an item inside for testing, and click “Burn” in the upper right 
corner of the window.  
  
• When prompted, insert a blank disc and follow...

iMac (20-inch Early 2008)  — Symptom Charts  252
Optical drive does not accept CD / DVD disc
The optical drive on this computer has narrow tolerances for the recommended optical media. If 
the drive does not accept discs, the wrong kind of disc could be inserted.
Open the computer and slowly lift the panel. Verify that the four inverter-to-panel-cables are 
1. 
not resting on top of the optical drive. The inverter cables should be tucked into the open 
areas at the top and the bottom of the optical...

iMac (20-inch Early 2008)  — Symptom Charts  253
Fan Sound
Fans running at full speed after the computer turns on
The customer may have entered a diagnostic mode that causes the fans to run at full speed.* 1. 
Restarting the system will not restore normal fan operation. To solve the problem, the user or 
technician should follow instructions in the “General Information” chapter to  reset the SMC.
*Note: Customers reporting this symptom should be told to press the power button AFTER 
the power cord has...

iMac (20-inch Early 2008) 
 — Symptom Charts 
 254
System noisy, fails Apple Hardware Test for temp sensor 
Check the AHT error code on the 1.  Apple Hardware Test error code char t.
2.  Make sure the LCD temp sensor cable is connected to the sensor on the back of the LCD 
panel in the top right corner.
Make sure the LCD temp sensor cable is fully inserted into the connector on the bottom left 3. 
side of the logic board.  

iMac (20-inch Early 2008)  — Symptom Charts  255
Loud fan noise coming from inside the computer
The iMac has a trio of fans that circulate air throughout the system. It also includes temperature 
sensors, and advanced thermal software that spins the fans fast or slow as needed. As the system 
usage increases, the fans will adjust their speed using advanced thermal software to meet the 
cooling needs of the system.
Under normal conditions, rotating fans will make a slight hum that varies in relationship...

iMac (20-inch Early 2008)  — Symptom Charts  256
 
Yes: This is normal operation and none of the fans require replacement.
 
No: If the fan activity does not coincide with CPU usage, the sound you’re hearing may not 
be fan activity. Go to the Next Step.
The normal functioning of the hard drive and optical drive will generate additional whirring 
5. 
and scratching noises that may be audible. We can isolate these noises by booting the 
computer to the iMac Install Mac OS X Install Disc 1.  
 
- Place the...

iMac (20-inch Early 2008)  — Symptom Charts  257
Audible buzzing, whining, or ticking noise
The iMac contains several mechanical devices such as motors and fans that may make audible 
buzzing, ticking, or whining noises when they are operating in a normal manner. The sounds will 
vary depending on how the system is used.  
 
When troubleshooting abnormal noises try the following:
Verify that the computer is running a supported version of the Mac OS X operating system. 
1. 
If an earlier version of the...

iMac (20-inch Early 2008)  — Symptom Charts  258
AirPort
Not able to connect wirelessly with AirPort
1. From the Apple menu, choose About this Mac. 
2- Click on More Info. System Profiler should open. 
3- In System Profiler, in the column on the left, look under Network for a line called “AirPort Card”. 
Select that line. 
4- Does the section to the right say “No Information Found”? 
Yes: The computer doesn’t realize it has an AirPort card installed. Go to step. 5 
No: The iMac recognizes that it has an...

iMac (20-inch Early 2008)  — Symptom Charts  259
Bluetooth (also see Wireless Issues topic)
Bluetooth devices won’t sync with my computer
1. Make sure the computer has a Bluetooth board installed.  Open System Preferences (from the 
Apple menu, choose System Preferences) and verify that “Bluetooth” appears in the Hardware 
section of the window.
2. Locate the Bluetooth board inside the computer. Reseat the Bluetooth board, Bluetooth cable, 
and the Bluetooth antenna.
3 Turn on Bluetooth.  In System...

iMac (20-inch Early 2008)  — Symptom Charts  260
IR Remote
Remote won’t communicate with system applications such as iTunes or iPhoto, or 
with the optical drive
Make sure of the following when using the Apple Remote: 
You are within 30 feet of the front of the computer.
• 
You have an unobstructed line-of-sight to the front of the computer.• 
You are pointing the lens end of the Apple Remote directly at the front of the computer.• 
The computer is powered on and awake.• 
The “Disable remote control...