Install the rear H100/H200 GPU cold plate module

Follow instructions in this section to install the rear H100/H200 GPU cold plate 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.
• Touch the static-protective package that contains the component to any unpainted metal surface on the server; then, remove it from the package and place it on a static-protective surface.
• A torque screwdriver is available for request if you do not have one at hand.

Note

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

• Torx T10 head screwdriver
• Torx T15 head screwdriver
• Phillips #1 head screwdriver
• Phillips #2 head screwdriver
• Flat head screwdriver
• Alcohol cleaning pad
• H100/H200 PCM Kit
• SR780a V3 water loop putty pad kit
• SR780a 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.

The following illustration shows the GPU numbering and corresponding slot numbering in XCC.

Figure 1. GPU numbering

The following illustration shows the components for rear H100/H200 GPU cold plate module.

Figure 2. rear H100/H200 GPU cold plate module components identification

Table 1. rear H100/H200 GPU cold plate module components

1 Manifold	2 Hose tie
3 leakage sensor module	4 Shipping bracket
5 GPU cold plate	6 GPU slot number label
7 GPU cold plate screw torque label

Procedure

1. Make sure the GPU complex is installed in the chassis.
2. Replace the Phase Change Material on the rear H100/H200 GPU cold plate module.
   1. Remove the liner from one side of the pad.
   2. Align the PCM with the marking on the bottom of the cold plate, and place it onto the cold plate; then, apply finger pressure across the entire surface area of the PCM to remove any trapped air and allow 1-2 minutes dwell time until it is firmly attached. Carefully remove the remaining top liner.
   3. Repeat to replace the PCM on the four cold plates.
      Attention

      • PCM cannot be reused. PCM must be replaced with new ones every time the water loop is removed.

      • After PCM is replaced, there is an expected short duration of throttling before the GPU returns to normal operation. This is due to the PCM requiring a break-in period after being replaced.

      Figure 3. PCM application
      
      
3. Replace the putty pads (x5) on the GPU.
   1. Remove the liner from one side of the pad.
   2. Make sure to align the putty pads to the GPU VR (1) and the markings on GPU; then, place the pads onto the GPU and apply light finger pressure across the entire surface area of the pads to ensure adhesion. Carefully remove the remaining top liner.
   3. Repeat to replace all putty pads on the four GPUs.
      Attention

      Putty pad cannot be reused. Putty pad must be replaced with new ones every time the water loop is removed.

      Figure 4. GPU putty pads replacement
      
      

      1 GPU VR (Cover the GPU VR with putty pad)

4. Install the rear H100/H200 GPU cold plate module.
   1. Hold the rear H100/H200 GPU cold plate module by the shipping brackets; then, align the guide slots on the manifold with the guide pins marked with A and gently place the cold plate module onto the four rear GPUs.
   2. Ensure the guide slots on the manifold are securely engaged with the guide pins marked with A on the chassis.
      Figure 5. Installing the rear H100/H200 GPU cold plate module
      
      
5. Loosen the six captive screws that secure the shipping brackets to the rear H100/H200 GPU cold plate module; then, remove the shipping brackets from the rear H100/H200 GPU cold plate module.
   Figure 6. Removing the shipping brackets
   
   
6. Adjust the cold plate until the two guide pins are seated in the guide holes on the GPU. Repeat to adjust the four cold plates.
   Figure 7. Adjusting the GPU cold plates
   
   
7. Follow the screw sequence specified on the cold plate label, and repeat to fully tighten the sixteen Torx T10 screws with a torque screwdriver set to the proper torque.
   1. Set the torque screwdriver to 0.4±0.05 newton-meter, 3.5±0.5 pound-inch.
   2. Fasten the screws 720s degree following the screw installation sequence: → → →
      Note

      Make sure to follow screw installation sequence to prevent GPU cold plate tilting.
   3. Repeat until all screws on the four GPU cold plates are fully tightened.
   Figure 8. Repeat to fully tighten all the screws
   
   

   Figure 9. Installing the GPU cold plates
   
   
8. The following illustration shows the hose holder location.
   Figure 10. Hose holder location
   
   
9. Place the hoses on the hose guides and the hose holders.
   1. Place the rear H100/H200 GPU cold plate module hoses and cables on the hose guides, and secure them with hose ties. See Fan control board cable routing and Leakage sensor module cable routing.
      Figure 11. Securing the hoses and cables with hose ties
      
      
   2. Place the left side rear H100/H200 GPU cold plate module hose on (1) hose holder C, and the right side rear H100/H200 GPU cold plate module hose on (2) hose holder B. Ensure the guiding labels on the hoses match with the markings on the hose holders.
      Figure 12. Placing the hoses on hose holders
      
      

      1 Hose holder C (left side)

      2 Hose holder B (right side)

      Important

      • Check the guiding labels on the hoses and hose holders before installation.

10. Reposition the rear H100/H200 GPU cold plate module manifold as illustrated.
    1. Disengage the manifold from the guide pins marked with A; then, move the manifold to the guide pins marked with B.
    2. Ensure the guide slots on the manifold bracket are securely engaged with the guide pins marked with B.
       Figure 13. Repositioning the rear H100/H200 GPU cold plate module manifold
       
       
11. Fasten the four M3 screws (W7-W8) (PH2, 4 x M3, 0.5 newton-meters, 4.3 inch-pounds) to secure the rear H100/H200 GPU cold plate module manifold to the chassis.
    Figure 14. Installing the rear H100/H200 GPU cold plate module manifold
    
    
12. If you are installing the rear H100/H200 GPU cold plate module after installing a new GPU complex, ensure that the NVSwitch cold plate module and the front H100/H200 GPU cold plate module are installed before installing the rear fan cage support bracket.
13. Install the rear fan cage support bracket.
    1. Align the rear fan cage support bracket with the corresponding screw holes; then, install the rear fan cage support bracket on top of hose holder B/C as illustrated.
    2. Fasten the four M3 screws (PH2, 4 x M3, 0.5 newton-meters, 4.3 inch-pounds) to secure the rear fan cage support bracket to the fan cage.
    3. Fasten the eight M3 screws (PH2, 8 x M3, 0.5 newton-meters, 4.3 inch-pounds) to secure the rear fan cage support bracket to the chassis.
       Figure 15. Installing the rear fan cage support bracket