Remove the NVSwitch cold plate module

Follow instructions in this section to remove the NVSwitch 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.
• 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 chassis from the rack. See Remove the server from rack.
• Two people and one lifting device on site that can support up to 400 lb (181 kg) are required to perform this procedure. If you do not already have a lifting device available, Lenovo offers the Genie Lift GL-8 material lift that can be purchased at Data Center Solution Configurator. Make sure to include the Foot-release brake and the Load Platform when ordering the Genie Lift GL-8 material lift.
• 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 T15 head screwdriver
• Phillips #1 head screwdriver
• Phillips #2 head screwdriver
• Flat head screwdriver
• Alcohol cleaning pad
• NVSwitch PCM Kit
• NVSwitch putty pad 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 NVSwitch cold plate module.

Figure 2. NVSwitch cold plate module components identification

Table 1. NVSwitch cold plate module components

1 NVSwitch cold plate torque label	2 leakage sensor module
3 Hose tie	4 Handle
5 NVSwitch cold plate	6 NVSwitch slot number label
7 Manifold

Procedure

1. Make preparation for this task.
   1. Remove the front top cover. See Remove the front top cover.
   2. Remove the rear top cover. See Remove the rear top cover.
   3. Remove the fan cage. See Remove the fan cage (trained technician only).
   4. Remove the CPU complex. See Remove the CPU complex.
   5. Remove the power complex. See Remove the power complex.
   6. Disconnect the cables and remove them from the GPU complex if necessary. Before disconnecting the cables, make a list of each cable and record the connectors the cable is connected to. Refer to Internal cable routing.
2. The following illustration shows the hose holder location.
   Figure 3. Hose holder location
   
   
3. Remove the rear fan cage support bracket.
   1. Unfasten the eight M3 screws that secure the rear fan cage support bracket to the the chassis.
   2. Unfasten the four M3 screws that secure the rear fan cage support bracket to the fan cage.
   3. Grasp the rear fan cage support bracket to lift it from the fan cage.
   Figure 4. Removing the rear fan cage support bracket
   
   
4. Unfasten the two captive screws that secure the hose holder in place; then, remove hose holder B/C. Repeat to remove hose holder B/C on the other side.
   Figure 5. Removing hose holder B/C
   
   
5. Release the hoses and cables from the hose ties that secure them to the hose guides.
   Figure 6. Release the hoses and cables from hose ties
   
   
6. Unfasten the three M3 screws that secure the hose guide to the chassis and the manifold; then, remove the hose guide. Repeat to remove the hose guide on the other side.
   Figure 7. Removing the hose guides
   
   
7. Follow the screw sequence specified on the cold plate label, and repeat to fully loosen the sixteen Torx T15 screws with a torque screwdriver set to the proper torque.
   1. Set the torque screwdriver to 0.57-0.61 newton-meter, 5-5.4 pound-inch.
   2. Loosen the screws 720 degrees following the screw sequence: → → →
      Note

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

   Figure 9. Removing the NVSwitch cold plates
   
   

   Note

   • If necessary, use a flat screwdriver to gently separate the cold plate and the NVSwitch from the corner of the cold plate. Ensure not the damage the NVSwitch or the cold plate.
   • Ensure the captive screws are completely loosen before removing the cold plate module.
8. Secure the hoses to the manifold with the hose ties. Hold the handles to lift the NVSwitch cold plate module out of the chassis.
   Figure 10. Removing the NVSwitch cold plate module
   
   
9. Immediately clean the PCM and putty pads off from the NVSwitches with alcohol cleaning pads. Gently clean the PCM and putty pads to avoid NVSwitch damages.
   Attention

   • It is recommended to clean the PCM while it is in liquid state.

   • The electrical components around the die on the GPUs are extremely delicate. When removing the PCM and cleaning the GPU die, avoid touching the electrical components to prevent damage.

   Figure 11. Cleaning PCM and putty pads off from the NVSwitches
   
   
10. With alcohol cleaning pads, wipe off any remaining putty pad and PCMs from the NVSwitch cold plate module.
    Figure 12. Wiping PCM and putty pads off from the cold plates