Apple imac 17 inch flat panel User Manual

 iMac (17-inch Flat Panel)  Take Apart - 99
 Neck Assembly• Remove the fan bracket.
• Remove the neck spoke retainer cap.
• Remove the blind mate connector screws.
• Remove the Faraday cage.
• Remove the outer plastic housing.
• Remove the flat panel display.
• Remove the back cover 
Procedure
The neck assembly is attached to the computer base at one end and to the flat panel 
display at the other end. To remove the neck assembly from the computer, follow all the 
take-apart procedures. When you are...

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 Service Source
Troubleshooting
iMac (17-inch Flat Panel) 

iMac (17-inch Flat Panel) Troubleshooting - 1
 General Information
General Information
What’s New and Different:
1.Important: If you are replacing the display, be sure to install the new display shield and EMI gaskets that 
come with the new LCD panel. Installation instructions are included with the new display panel. 
Additional display shields/gasket kits are also available separately as a kit, part #076-0958.
2. The LED and microphone are part of the display bezel (922-5297); they cannot be ordered...

2 - iMac (17-inch Flat Panel) Troubleshooting
 General Information could cause these parts to overheat. Short term separation, where the thermal pads are not handled 
excessively 
(an exception would be if you are simply testing the logic board and only detach it for a few 
minutes), does not require replacement. Refer to “Thermal Pad Installation” in this chapter for detailed 
information.
Refer to the Take Apart chapter, “Thermal Pad Installation.”
2.  Whenever the bottom housing is opened for service,...

iMac (17-inch Flat Panel) Troubleshooting - 3
 General Information
Logic Board, Top
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4 - iMac (17-inch Flat Panel) Troubleshooting
 General Information
Logic Board, Bottom
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iMac (17-inch Flat Panel) Troubleshooting - 5
 General Information
I/O Ports
Service Cables
Three extension cables (076-0897) are required when troubleshooting the iMac with the bottom 
housing open, as shown below. 
Important:  Diagnostic service cables allow the unit to run while the 
bottom housing is open; however, the computer cannot run for more than five minutes with the bottom 
housing open. If it is open longer, the CPU may overheat and become damaged.
Connect the cables as shown below. 
A= power...

6 - iMac (17-inch Flat Panel) Troubleshooting
 General Information
The PMU Chip
The PMU (Power Management Unit) is a microcontroller chip that controls all power functions 
for the computer. The PMU (location shown below) is a computer within a computer. It has 
memory, software, firmware, I/O, two crystals, and a CPU. Its function is to: 
• Tell the computer to turn on, turn off, sleep, wake, idle, etc.
• Manage system resets from various commands.
• Maintain parameter RAM (PRAM).
• Manage the real-time...

iMac (17-inch Flat Panel) Troubleshooting - 7
 General Information
Resetting the PMU on the Logic Board
Resetting the PMU (Power Management Unit) on the logic board can resolve many system 
problems. Whenever you have a unit that fails to power up, you should follow this procedure 
before replacing any modules.
1. Disconnect the power cord.
2. Remove the user access panel from the bottom of the computer.
3. Press the PMU reset switch (shown below) once on the bottom side of the logic board and then...

8 - iMac (17-inch Flat Panel) Troubleshooting
 General Information
Diagnostic Test Points
The iMac (17-inch Flat Panel) has four test points and one ground pad on the bottom of the logic board. 
These test points are accessible under the customer access panel via two small cutouts in the plastic 
shielding (see below).
These test points provide an easy troubleshooting tool for common problems. To use each test point, put 
the positive probe of your voltmeter on the test point, and the negative probe on...