Replace CPU and Heatsink (X8420 or X8440 Server Module)

You can replace a CPU and heatsink in a Sun Blade X8420 or X8440 Server Module (blade) that has been powered-off and removed from its chassis.

These components are a field-replaceable units (FRUs). They should be replaced only by qualified Sun service technicians.

This topic includes the following sections:

Preparing to Replace a CPU and Heatsink

  1. Prepare the blade for removal.

    See Prepare Components for a Hot-Remove Operation.

  2. Remove the blade from the chassis.

    See Replace Blade.

  3. Remove the blade cover.

    See Remove Blade Cover.

  4. Wear a properly grounded antistatic wrist strap.

    See About the Required Installation Tools and ESD.

Replacing a CPU and Heatsink

  1. Locate the CPU and heatsink you are replacing.

    The illustration below shows the CPUs and DIMMs on the X8420 Server Module. The CPUs and DIMMs on the X8440 Server Module are in a similar location. See X8440 Server Module CPU Locations.

  2. Use a 9/64 Allen wrench to loosen the two spring-loaded mounting screws that secure the heatsink to the motherboard. Hold down the top of the heatsink to prevent it from tipping unevenly while you alternately loosen the mounting screws. Turn each screw one-half turn (180 degrees) at a time, then remove the two screws and two springs when they are detached.

  3. Twist the heatsink slightly to reduce the adhesive and surface tension properties between the heatsink and CPU. Then lift the heatsink off of the board. Turn the heatsink upside down and allow the two washers in each of the two mounting holes to fall out into your hand.

    Note

    Set the heatsink upside down on a clean, flat surface to prevent the thermal grease from contaminating other components.

  4. Pull the CPU socket lever down and slightly away from the socket.

  5. Pivot the lever up, into the fully vertical, open position.

  6. Lift up the socket cover to expose the CPU.

  7. Lift the CPU out of the socket, leaving the lever and socket cover in the vertical, open position.

  8. Unpack the new CPU and heatsink (if a new heatsink was ordered).

  9. Ensure that the CPU socket release lever and socket cover is in the fully open, vertical position.

  10. Align and insert the CPU in the socket.

    Note

    Align the triangle that is printed on one corner of the CPU with the tiny triangle that is imprinted on the CPU socket.

    Caution

    The pins on the CPU socket are very fragile. If the CPU is correctly aligned, it will enter the CPU socket with little or no resistance. If you feel more than minimal resistance, stop and recheck the alignment. Forcing a misaligned CPU into the CPU socket could damage both devices.

  11. When the CPU is fully seated in the socket, close the socket cover and pivot the release lever down and into the locked position, under the hook at the side of the socket.

  12. Perform one of the following, depending if you are reinstalling an existing heatsink or installing a new heatsink.

    • If you are reinstalling an existing CPU or heatsink, remove any heavy amounts of thermal grease with a tissue. Then use an alcohol pad to clean all old thermal grease from the component surfaces. Continue with Step 13.

    • If you are installing a new heatsink, the heatsink will have preapplied thermal grease that is protected with a plastic cover. Remove the plastic cover. Do not apply any more thermal grease to the heatsink. Go to Step 14.

      Caution

      Do not apply additional thermal grease to a new heatsink that comes with preapplied grease. Too much grease will ooze out and possibly go down into the socket, damaging the components.

  13. Use one syringe of thermal grease (1 ml) to carefully apply grease to the top of the CPU in two lines that make an X pattern and a third line placed horizontally across the mid section of the X.

    Caution

    Ensure that the thermal grease in the syringe supplied with the CPU is pliable and not stiff. If the syringe of grease has aged, the grease may be too stiff to adequately spread out and provide thermal conductance.

  14. Turn the heatsink upright and reinstall the two washers, two springs, and mounting bolts.

  15. Carefully position and align the heatsink over the CPU.

    Caution

    Avoid moving the heatsink after it has contacted the top of the CPU. Too much movement could disturb the layer of thermal grease, leading to component damage.

  16. Lower the heatsink onto the CPU, aligning the mounting bolts with their holes on the motherboard.

  17. Alternately tighten the two heatsink mounting screws one-half turn (180 degrees) at a time until each spring is compressed and the screw bottoms out on the mating surface. Hand tighten–do not force–the screws approximately 8 in/ounce.

Finishing the CPU and Heatsink Replacement

  1. Reinstall the blade cover.

    See the installation instructions in Remove Blade Cover.

  2. Insert the blade into the chassis.

    See the installation instructions in Replace Blade.