Procedure

1. Remove the three metal torx screws and the one plastic screw.

2. Grab the logic board by the battery retainer and the hard drive connector. Lift the board and pull back to release the board from the bottom housing and I/O ports. Note: The I/O port covers may come out with the logic board when it's removed.

3. Remove the I/O port covers from the logic board.

Warning: Whenever the bottom housing is opened for service, you must do two things:

  1. You must clean the original thermal film from the surfaces joining the thermal interface layer and reapply thermal paste to the thermal pipe.
  2. You must tighten the four torx screws on the bottom housing to a minimum of 17 in.-lbs. If you do not have a torque driver, you will have to make sure these screws are tightened by hand FIRMLY, BUT NOT FORCIBLY. Or, purchase the service tool (076-0899) in order to ensure the thermal pipe is firmly mated with the top base. If the bottom housing is not securely attached to the base in this fashion, the CPU may overheat and become damaged. Failure to follow either of these steps could cause the computer to overheat and damage internal components.

Refer to the topic, "Thermal Paste Application" for detailed information.

Warning: Whenever the logic board is separated from the bottom housing, you must install new thermal pads to three surfaces on the bottom housing. The thermal pads help cool components on the logic board. Failure to apply these pads whenever the logic board is separated from the bottom housing 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.

Important: Diagnostic service cables allow the unit to run while the bottom housing is open (as shown above). 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.

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