Apple imac usb 2 0 User Manual

							
42 - iMac (USB 2.0)  Take Apart
 Drive Carrier Assembly (Optical and Hard Drive)
Procedure
1. Rotate the base unit so the optical drive door is facing to the right.
2. Remove six screws; two on the EMI shield (with copper tape) and four attaching the 
drive to the Faraday cage (chassis). Carefully lift the shield and copper tape off the 
drive.  Replacement Note:  When replacing the drive EMI shield, be sure to use the 
two shorter screws.  
						

							
 iMac (USB 2.0)  Take Apart - 43
 Drive Carrier Assembly (Optical and Hard Drive) 3. Remove the Airport and Bluetooth antennas from the plastic clip on the side of the 
drive carrier. 
						

							
44 - iMac (USB 2.0)  Take Apart
 Drive Carrier Assembly (Optical and Hard Drive)
4. Grasp the carrier by the top and bottom edges. Wiggle the drive carrier out of the 
chassis pulling the carrier in the direction of the arrow.  Note: The carrier fits snugly 
into the chassis.
5. Disconnect the two power cables; one attaches to the optical drive and the other  attaches to the hard drive. 
						

							
 iMac (USB 2.0)  Take Apart - 45
 Drive Carrier Assembly (Optical and Hard Drive) 6. To remove the hard drive from the carrier, peel the white wrapper up to access the 
screws (two on each side). Remove the screws, disconnect the data cable, and 
remove the hard drive out of the carrier.   
7. To remove the optical drive, remove four screws (shown by dashed lines), disconnect  the optical drive data cable (see lower arrow), and slide the optical drive out of the 
carrier. 
						

							
46 - iMac (USB 2.0)  Take Apart 8.
Note:  The drive carrier on the 20-inch iMac (USB 2.0), 922-6216, is different from the 
drive carrier used on the 15-inch and the 17-inch iMac (USB 2.0) computers. The 20-
inch iMac (USB 2.0) drive carrier is shown below. 
Warning:  Whenever the bottom housing is opened for service, you must do two things:
1.You must clean the original thermal film from all thermal interface ma\
ting surfaces, 
and reapply thermal paste to the mating surfaces on the thermal pipe.
2. You must tighten the four torx screws on the bottom housing to a mini\
mum of 17 
in.-lbs. Use a torque driver (service tool 076-0899) to ensure that th\
e thermal pipe is 
firmly mated with the top base. If you do not have a torque driver, you \
must make 
sure the screws are tightened by hand FIRMLY, BUT NOT FORCIBLY. 
Failure to follow these steps could cause the computer to overheat and 
damage internal components.
Refer to the topic “Thermal Paste Application” for detailed inform\
ation. 
						

							
 iMac (USB 2.0)  Take Apart - 47
 Power Supply
Power Supply
Tools
This procedure requires the following tools:
• Torx-10 screwdriver
Part Location
Preliminary Steps
Before you begin, do the following:
• Position the computer in the service stand and rotate the door to the ri\
ght.
• Remove the user access plate.
• Remove the bottom housing.
• Remove the drive carrier assembly. 
						

							
48 - iMac (USB 2.0)  Take Apart
 Power Supply
Procedure
1. Remove the two power supply screws circled below.  
						

							
 iMac (USB 2.0)  Take Apart - 49
 Power Supply 2. Open the optical drive door as shown. Support the metal plate and power supply as 
you remove the four screws.
 Important:  The two screws near the door hinge are shorter than the other power 
supply screws. Failure to replace the shorter screws into their correct location will 
scratch the top housing. See step 4, Replacement Note. 
						

							
 
50 -  
 iMac (USB 2.0)  Take Apart  Power Supply
3. Lift the power supply and metal shield out of the chassis (Faraday cage). 
4.
 
Note:  
 The power supply on the 20-inch iMac (USB 2.0), 661-3104, is different from 
the power supply used on the 15-inch and the 17-inch iMac (USB 2.0) computers\
. The 
20-inch iMac (USB 2.0) power supply is shown below.  
						

							
 
 iMac (USB 2.0)  Take Apart -   
51
 
 Power Supply 5.
 
Replacement Note:
 
  When replacing the metal shield (see picture above) that sits on 
top of the power supply, install the two shorter screws near the optical door. If the 
longer screws are installed by mistake, the screws will scratch the inside of the 
housing (circled below).
 
Warning:  
 Whenever the bottom housing is opened for service, you must do two things:
1.You must clean the original thermal film from all thermal interface ma\
ting surfaces, 
and reapply thermal paste to the mating surfaces on the thermal pipe.
2. You must tighten the four torx screws on the bottom housing to a mini\
mum of 17 
in.-lbs. Use a torque driver (service tool 076-0899) to ensure that th\
e thermal pipe is 
firmly mated with the top base. If you do not have a torque driver, you \
must make 
sure the screws are tightened by hand FIRMLY, BUT NOT FORCIBLY.   
Failure to follow these steps could cause the computer to overheat and 
damage internal components.  
Refer to the topic “Thermal Paste Application” for detailed inform\
ation.