Attention: Do not touch the thermal material on the bottom of the heat sink.Touching the thermal material will contaminate it. If the thermal material on themicroprocessor or heat sink becomes contaminated, contact your servicetechnician.a. Make sure that the thermal material is still on the bottom of the heat sink;then, align the heat sink so that the arrows on the label point toward theDIMMs and place the heat sink on top of the microprocessor, thermalmaterial side down.HeatsinkOrientationDIMMsDIMMsb. Align the screws on the heat sink with the screw holes on the systemboard.c. Tighten the screws with a screwdriver, alternating among the screws untilthey are tight. If possible, each screw should be rotated two full rotations ata time. Repeat until the screws are tight. Do not overtighten the screws byusing excessive force.Attention: When the two screws that are closer to the rear of the serverare tightened, the screw heads are not level with the surface of the heatsink. Do not overtighten the screws by using excessive force.7. Replace the air baffle (see “Installing the DIMM air baffle” on page 133).8. Install the cover (see “Installing the cover” on page 130).9. Slide the server into the rack.10. Connect the cables and power cords.11. Turn on all attached devices and the server.Thermal greaseThe thermal grease must be replaced whenever the heat sink has been removedfrom the top of the microprocessor and is going to be reused or when debris isfound in the grease.When you are installing the heat sink on the same microprocessor that it wasremoved from, make sure that the following requirements are met:v The thermal grease on the heat sink and microprocessor is not contaminated.v Additional thermal grease is not added to the existing thermal grease on the heatsink and microprocessor.Note:1. Read the safety information that begins on page vii.2. Read “Installation guidelines” on page 127.3. Read “Handling static-sensitive devices” on page 129.188 IBM System x3250 M3 Types 4251, 4252, and 4261: Problem Determination and Service Guide
