Apple imac 17 inch late 2006 User Manual

							iMac (17-inch Late 2006) Troubleshooting — General Info 141
DDR Memory
The iMac (17-inch Late 2006) computer has two SDRAM slots in the bottom of the computer. 
The iMac ships from the factory with at least 1GB of DDR2 SDRAM, installed as a 512 MB DIMM in 
the top slot and a 512 MB DIMM in the bottom slot. ( The computer may come with more RAM, 
depending on how the computer was ordered from Apple.) The system can support up to 3 GB 
of memory. If you install two 2GB DIMMs, the “About this Mac” will show 4GB of memory installed, 
however; the system will only utilize 3GB of memory.
You can use small-outline dual inline memory modules (SO-DIMMS) that meet all of these criteria:PC2-5400
• 
unbuffered
• 
nonparity
• 
200-pin
• 
667 MHz DDR2 SDRAM
• 
Note:  DIMMs with any of the following features are NOT supported in this iMac:
registers or buffers
• 
PLLs
• 
ECC
• 
parity
• 
EDO RAM
•  
						

							iMac (17-inch Late 2006) Troubleshooting — General Info 142
How to Reset the System Management Controller (SMC)
The System Management Controller (SMC) is a chip on the logic board that controls all power 
functions for your computer. If your computer is experiencing any power issue, resetting the SMC 
may resolve it. The SMC controls several functions, including:Telling the computer when to turn on, turn off, sleep, wake, idle, and so forth.
• 
Handling system resets from various commands.
• 
Controlling the fans.
• 
Note that resetting the SMC does not reset the PRAM. Resetting the SMC will not resolve issues 
in which your computer is unresponsive—in these situations, restarting your computer will 
generally suffice. If your computer isn’t responding, perform these steps one at a time, in this 
order, until the issue has been resolved:
Force Quit (Option-Command-Escape).
1.  
Restart (Control-Command-Power).
2.  
Force Shut Down (press the power button for 10 seconds).
3. 
Resetting the SMC can resolve some computer issues such as not starting up, not displaying 
video, sleep issues, fan noise issues, and so forth. If your computer still exhibits these types of 
issues after you’ve restarted the computer, try resetting the SMC.
To reset the SMC on an iMac (17-inch Late 2006)
From the Apple menu, choose Shut Down (or if the computer is not responding, hold the 
1.  
power button until it turns off ).
Unplug all cables from the computer, including the power cord.
2.  
Wait at least 15 seconds.
3. 
Plug the power cord back in, making sure the power button is not being pressed at the same 
4.  
time. 
Reconnect your keyboard and mouse to the computer.
5. 
Press the power button on the back to start up your computer.
6.   
						

							iMac (17-inch Late 2006) Troubleshooting — General Info 143
Diagnostic LEDs
The iMac (17-inch Late 2006) has three built-in diagnostic LEDs and a front power-on/sleep LED 
on the main logic board that can help you to troubleshoot the computer.
To Access the Diagnostic LEDs:v
Follow the take apart instructions to remove the RAM 
1.   access door, front bezel, and lower EMI 
shield.
Locate the SO-DIMM slot and LVDS video connector. The three diagnostic LEDs 1, 2, and 3 are 
2.  
located to the left of the battery and under the SATA cable. Note that the LEDs are marked 1, 
2, 3 from left to right, as show below. An additional front bezel LED is located in an opening 
at the center of the right speaker, as shown below.   
 LED #1  Indicates that the trickle voltage from the power supply has been detected by the main 
• 
logic board. This LED will remain ON whenever the iMac is connected to a working AC power 
source. The LED will remain on even when the computer has been shut down or put to sleep. 
The LED will turn off only if the AC power source is disconnected or the power supply is 
faulty.
LED #2 Indicates that the main logic board has detected proper power from the power supply when 
• 
the computer is turned on. This LED will be ON when the computer is turned on and the 
power supply is working correctly. 
						

							iMac (17-inch Late 2006) Troubleshooting — General Info 14 4
LED #3
Indicates that the computer and the LCD display are communicating. This LED will be ON 
• 
when the computer is turned on and video signal is being generated.
Front LED Indicates that the computer has power but no video signal (e.g., the computer is starting up 
• 
or the display has entered Sleep mode, turning off the video signal). This LED will pulse when 
the entire system has entered Energy Saver mode.   
						

							iMac (17-inch Late 2006) Troubleshooting — Symptom Charts 145
Symptom Charts
How to Use the Symptom Charts
The Symptom Charts included in this chapter will help you diagnose specific symptoms related 
to the product. Because cures are listed on the charts in the order of most likely solution, try 
the cures in the order presented. Verify whether or not the product continues to exhibit the 
symptom. If the symptom persists, try the next cure. 
Note:  If a cure instructs you to replace a module, reinstall the original module before you 
proceed to the next cure. 
						

							iMac (17-inch Late 2006) Troubleshooting — Symptom Charts 146
Power Issues
No Power 
The iMac (17-inch Late 2006) will not turn on. The display remains black and there are no sounds 
from the fans or drives.
1. Verify the power outlet is good. Plug a different device into the socket to ensure there is power, 
or plug the iMac into another outlet. Does the iMac power on now?Ye s: Resolved. Bad outlet.
No : Go on to the next step.
2. Check the power cord. Use a known good power cord. Does the iMac power on  now? Ye s: Your power cord has failed. Replace the AC power cord.
No : Go on to the next step.
3. Check the connection of the power cord on both ends. Verify that the power cord is securely 
plugged into both the AC outlet and back of the computer. Does the iMac power on now? Ye s: You may have a loose fit to your power cord. Replace the AC power cord and test.
No : Go on to the next step.
4. Follow instructions in the General Information chapter to reset the SMC. Does the iMac power 
on now? Ye s: Issue resolved.
No : Go on to the next step.
5.  Remove and reinstall the SO-DIMM memory modules, located in the bottom of the 
computer. Does the iMac power on now? Ye s: Issue resolved.
No : Go on to the next step.
6. Remove the RAM access door, front bezel, and lower EMI shield to gain access to the three 
diagnostic LEDs.  See “Diagnostic LEDs” in the General Information chapter for complete 
instructions on this procedure.
7. Plug the power cord into the iMac and the power cord into the AC outlet. Check to see if LED 
#1 is On or Off. LED #1 is On: This indicates that the power supply is getting good power from the AC outlet. 
Go on to the next step.
LED #1 is Off: This indicates that either the power inlet assembly or the power supply should 
be replaced. 
						

							iMac (17-inch Late 2006) Troubleshooting — Symptom Charts 14 7
8  Press the power button. Check to see if LED # 2 comes On, comes on momentarily, or stays Off.
LED # 2 is On: The Power Supply is functioning. Go on to the next step.
LED # 2 comes on momentarily or stays Off: Replace the Power Supply.
9. At this point in the Power On process, you should hear a boot chime and see the front LED on 
the computer light up. When the main logic board and LCD panel communicate to deliver video, 
the front LED should go off, and LED # 3 should be on. Does the Front LED go off? Ye s: The LCD and main logic board have communicated. If there is no picture on the display, 
follow “No Video” troubleshooting.
No : Your logic board is not communicating with LCD panel.  Go on to the next step.
10. Check to see if LED # 3 is On or Off. LED # 3 is On: The logic board is communicating with LCD panel. Follow “No Video” 
troubleshooting.
LED # 3 is Off: The logic board is not communicating with LCD panel. Reseat the LVDS cable 
and test again. If the issue persists, replace the main logic board.
Audible buzzing, whining, or ticking noise
The iMac (17-inch Late 2006) 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 operating system has been installed then the fans may run at 
excessive speeds. 
Determine that this noise is related to the computer by removing and shutting down all 
2.  
other devices in the vicinity of the computer that could be causing a sound.
Eject any media inserted into the optical drive. The optical drive will make a variety of normal 
3. 
sounds when accessing the optical media.
Quit all applications and test the computer again. Processor intensive applications may cause 
4.  
the fans to run at a higher RPM and therefore be more audible.
 Boot to the latest version of Apple Service Diagnostic for iMac (17-inch Late 2006) and 
5. 
select the EFI test suite by holding down the D key during startup.  The diagnostic tests fan 
speeds and thermal sensor functionality.  Should tests fail, replace any parts indicated by the 
diagnostic.
Reboot the computer and check the computer again. If the noise persists and is unusually 
6.  
loud, contact Apple Technical Support. 
						

							iMac (17-inch Late 2006) Troubleshooting — Symptom Charts 14 8
No Video
No Video, No Boot Chime, White LED ON (Symptom 1)
The iMac (17-inch Late 2006) will turn on (indicated by the front LED ON), but there is NO boot 
chime and No Video on the display. The faint sound of the fans, hard drive, and optical drive may  
also be heard.
1. Follow instructions in the “General Information” chapter to reset the SMC. Does the computer 
display video after successfully resetting the SMC?Ye s: Problem solved.
No : Continue to next step.
2.  Verify that only supported SDRAM memory has been installed and that it has been installed 
correctly. Unsupported and/or defective memory can prevent the iMac (17-inch Late 2006) from 
booting. It may be necessary to install known good memory for testing purposes and replace any 
unsupported or defective SO-DIMM’s identified during this process. Does the computer display 
video after verifying and/or replacing the memory with known good memory? Ye s: Problem solved. Verify full system functionality before return the system to the customer.
No : Replace the logic board.
No Video, Boot Chime heard, White LED ON  (Symptom 2)
The iMac (17-inch Late 2006) will turn on, the boot chime can be heard, a white LED appears on 
the front bezel and sounds from the fan or drive activity can be heard, but the display has no 
picture or color.  
1. Check if the computer is sleeping. Press the space bar to wake the computer from sleep mode. 
Did the computer wake from sleep? Yes: Put the computer to sleep from the Apple menu and wake the computer again to test. 
Check Energy Saver setting to see when the computer has been designated to sleep.
No: Continue to next step.
2. Reset your computer’s PRAM (Parameter RAM): If your iMac is on, turn it off by holding the power button until the unit powers off. You 
 
-
should hear the fans go quiet.
 While the computer is off, with your left hand, hold down the Apple key, the Option key 
 
-
next to it, and the letter “R” key on the keyboard. When you have these keys all pressed 
down, push the power button with your right hand and then quickly move that hand 
to hold down the letter “P” on the keyboard. Keep these four keys pressed while the 
computer starts up.
 Make sure you hold down the four keys (P - R - Apple - Option) while the computer is 
 
-
starting up. When you hear the computer’s start up chime for the second time, you can 
let go of the keys on the keyboard. 
						

							iMac (17-inch Late 2006) Troubleshooting — Symptom Charts 149
If you didn’t hear at least two startup chimes, go to the top of this section and begin 
 
-
again. It’s important that you hear two startup chimes when performing this procedure. 
This indicates that you have successfully reset the computer’s PRAM (Parameter RAM).
3. Does the computer display video after successfully resetting the computer’s PRAM? Ye s: Restart the computer from the Apple menu and make sure the computer is now 
working correctly.
No : Continue to next step.
4. Make sure the machine is powered off; power off the machine by holding in the Power Button 
on the rear of the machine. Turn on the machine. Observe the white LED on the front bezel 
during startup; it should go out after a few moments. Did the LED go off? Ye s: If the LED went off, this indicates that the main logic board has communicated with the 
LCD display for video signal and your main logic board should be good. You can confirm by 
connecting an external monitor and checking to see that you have video out. Go to Step 7.
No : Continue with the next step to reset system power management (SMC).
5. Follow instructions in the “General Information” chapter to reset the SMC. Does the computer 
display video after successfully resetting the SMC?  Ye s: Press and hold the power button until the computer powers off. Start the computer 
again and confirm that front LED is reliably going off. If the computer still has no video but 
the LED is reliably going off, continue with step 7.
No : Go to the next step.
6. Unplug the iMac and remove the SDRAM. Replace with known good SDRAM. Plug the iMac   
back in and power the unit on. Does the front LED go off after a few moments now? Ye s: Replace the original SDRAM and test again. If the front LED does not go off with the only 
the original SDRAM installed, replace the SDRAM. If the LED is now reliably going off after a 
few moments, but yet you still do not have any video, go to step 7.
No : If the LED remained on, the main logic board is not communicating with the LCD panel 
to generate video. Replace the main logic board.
7. With the LED going off, you may have a No Backlight condition or an LCD failure. In a dim room, 
turn the display at an angle to you and look closely at the display. Is the display completely black 
or can you see a dim, purplish light or glow to the display? Completely black: Replace the inverter
 
-
Dim purplish light or glow: Replace the LCD panel.
 
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							iMac (17-inch Late 2006) Troubleshooting — Symptom Charts 150
Display is tinted another color.
Reset the parameter RAM. Press the Command-Option-P-R keys. When you keep all the keys 
1.  
held down, you will hear the startup chime over and over again (about every ten seconds) 
until you let go. After you hear the second chime, you can let go of the keys. 
Does the computer display video after successfully resetting the computer’s PRAM? 
Yes: Problem resolved. Restart the computer from the Apple menu and make sure the 
computer display is no longer tinted another color. 
No: Continue to the next step.
Connect an external monitor to the mini-VGA port. Does the external display exhibit the 
2.  
same color tinting?  
Yes: Replace the logic board. 
No: Check the LVDS cable connection. If connected and same color tinting persists, replace 
the LVDS cable. Does color tinting persist after changing the LVDS cable? 
  Yes: Replace the LCD display panel. 
  No: Problem solved. Restart the computer from the Apple menu and make sure the 
computer display is no longer tinted another color.