Remove the Lenovo Neptune liquid-to-air (L2A) hybrid cooling module

Follow instructions in this section to remove the Lenovo Neptune liquid-to-air (L2A) hybrid cooling module. The procedure must be executed by a trained technician.

About this task

Attention

• Read Installation Guidelines and Safety inspection checklist to ensure that you work safely.
• Power off the server and peripheral devices and disconnect the power cords and all external cables. See Power off the server.
• If the server is installed in a rack, slide the server out on its rack slide rails to gain access to the top cover, or remove the server from the rack. See Remove the server from rack.

CAUTION

Do not touch the radiator fins. Touching the radiator fins might damage the L2A.

Note

Make sure you have the required tools listed below available to properly replace the component:

• Phillips #1 bit
• Torx T15 bit
• Manual torque screwdriver
• DIMM tool
• Alcohol cleaning pad
• SXM5 PCM Kit
• SR675 V3 water loop putty pad kit
• SR675 V3 water loop service kit

Important

Putty pad/phase change material (PCM) replacement guidelines

• Before replacing the putty pad/PCM, gently clean the hardware surface with an alcohol cleaning pad.
• Hold the putty pad/PCM carefully to avoid deformation. Make sure no screw hole or opening is blocked by the putty pad/PCM.
• Do not use expired putty pad/PCM. Check the expiry date on putty pad/PCM package. If the putty pads/PCM are expired, acquire new ones to properly replace them.

Procedure

1. Make preparation for this task.
   1. Remove the top cover. See Remove the top cover.
   2. Remove all of the fans. See Remove a fan.
   3. Remove the fan cage. See Remove the fan cage.
   4. Unfasten the two cable ties on the front drive tray to release the cables.
      Figure 1. Unfastening the cable ties
      
      
   5. Depending on the configuration, remove the front PCIe adapter(s) or the OSFP port card. See Remove a front PCIe adapter or Remove the OSFP port card.
   6. Disconnect the following cables from the system board assembly:
      • Front I/O module cables
      • Front operator panel cable

      Attention

      To avoid damaging the system board assembly, make sure to follow the instructions in Internal cable routing when disconnecting cables from the system board assembly.

   7. Depending on the configuration, remove all of the 2.5-inch hot-swap drives and the drive bay fillers (if any) or all of the E3.S hot-swap drives and the drive bay fillers (if any). See Remove a 2.5-inch hot-swap drive or Remove an E3.S hot-swap drive. Place the drives on a static protective surface.
   8. Depending on the configuration, disconnect the power and signal cables from the 2.5-inch drive backplane or the E3.S dive backplane.
   9. Depending on the configuration, remove the 2.5-inch drive cage or the E3.S drive cage assembly. See Remove the 2.5-inch drive cage or Remove the E3.S drive cage assembly.
   10. Depending on the configuration, remove the CX-7 assembly or the SXM5 PCIe switch board. See Remove the CX-7 assembly or Remove the SXM5 PCIe switch board.
   11. Remove the front drive tray. See Remove the front drive tray.
   12. Depending on the configuration, remove the front I/O expansion board carrier or the front I/O expansion board module. See Remove the front I/O expansion board carrier or Remove the front I/O expansion board module.
   13. Remove the interposer card. See Remove the interposer card.
2. Hold the strap on the SXM5 GPU board assembly power cable, and disconnect it from the SXM5 GPU board assembly and the SXM5 GPU power distribution board.
   Figure 2. SXM5 GPU board assembly power cable disconnection

   
   
   
3. Hold the radiator by its upper edge and hold the cold plate assembly by its lifting handle; then, lift the GPU-L2A assembly out of the chassis.
   Figure 3. GPU-L2A assembly removal
   
   
4. Remove the six Phillips #1 screws (M3 x 5 mm) that secure the radiator to the GPU tray.
   Note

   Loosen or tighten the screws with a torque screwdriver set to the proper torque. For reference, the torque required for the screws to be fully loosen or tighten is 0.45+0 /- 0.06 newton-meter, 4.0+0/- 0.5 inch-pound.

   Figure 4. Phillips #1 screw removal
   
   

   1 Radiator

   2 Cold plate assembly

5. Remove the cold plate screws (sixteen Torx T15 screws).
   Important

   • Make sure to use the manual torque screwdriver in this step.
   • Make sure to follow screw removal sequence specified on the cold plate label to prevent cold plate tilting.
   • Loosen or tighten the screws with a torque screwdriver set to the proper torque. For reference, the torque required for the screws to be fully loosen or tighten is 0.45+0 /- 0.06 newton-meter, 4.0+0/- 0.5 inch-pound.
   1. Follow the screw removal sequence (screw 1 > 2 > 3 > 4), and loosen each of the four screws on the cold plate 4 by 360 degrees. Repeat to ensure all screws are fully loosened.
   2. Follow the screw removal sequence (screw 1 > 2 > 3 > 4), and loosen each of the four screws on the cold plate 3 by 360 degrees. Repeat to ensure all screws are fully loosened.
   3. Follow the screw removal sequence (screw 1 > 2 > 3 > 4), and loosen each of the four screws on the cold plate 2 by 360 degrees. Repeat to ensure all screws are fully loosened.
   4. Follow the screw removal sequence (screw 1 > 2 > 3 > 4), and loosen each of the four screws on the cold plate 1 by 360 degrees. Repeat to ensure all screws are fully loosened.
   Figure 5. Torx T15 screw removal
   
   
6. Disengage the four cold plates from the SXM5 GPUs.
   1. Insert the DIMM tool into the gap between the cold plate and GPU, beneath the round hole on the cold plate, as shown in the illustration.
   2. Gently press down the DIMM tool to disengage the cold plate from the GPU.
   3. Repeat steps 6a and 6b to disengage the remaining three cold plates from the GPUs.
   Attention

   Ensure the DIMM tool is not inserted beyond the round hole to avoid damaging the GPUs.

   Figure 6. Cold plate disengagement
   
   
7. Hold the radiator by its upper edge and hold the cold plate assembly by its lifting handle; then, lift the L2A from the SXM5 GPU board assembly.
   Figure 7. L2A removal
   
   
8. Turn the L2A upside down.
   1. Hold the radiator by its upper edge and hold the cold plate assembly by its lifting handle; then, put the L2A into the shipping box.
   2. Place the top cover of the shipping box on top of the L2A and ensure it is firmly seated.
   3. Hold the shipping box and carefully turn it upside down.
   4. Remove the bottom cover of the shipping box.
   5. Remove the plastic tray and the bottom of the cold plate assembly is facing up.
      Figure 8. Turning the L2A upside down
      
      
      
      
9. Wipe any remaining PCM and putty pads off from all the cold plates with alcohol cleaning pads.
   Figure 9. Wiping PCM and putty pads off from the cold plates
   
   
10. Gently wipe any remaining PCM and putty pads off from all the SXM5 GPUs with alcohol cleaning pads to avoid SXM5 GPU damages.
    Attention

    The electrical components around the die on the SXM5 GPUs are extremely delicate. When cleaning the SXM5 GPU die, avoid touching the electrical components to prevent damages.

    Figure 10. Wiping PCM and putty pads off from the SXM5 GPUs