Remove the front B200 GPU cold plate module

Follow instructions in this section to remove the front B200 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
• Torx T15 200mm extension bit
• Phillips #1 head screwdriver
• Phillips #2 head screwdriver
• Alcohol cleaning pad
• B200 PCM
• B200 SXM6 PAD-1
• B200 SXM6 PAD-2
• B200 GPU F&R Shipping bkt Kit
• B200 GPU Service Kit

B200 (GPU & Retimer NVSwitch) (service & shipping bkt) Kit are reusable and mandatory when servicing GPUs and GPU cold plate modules. It is recommended to keep them at the facility where the server operates for future replacement needs.

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 B200 GPU numbering and corresponding slot numbering in XCC.

Figure 1. B200 GPU numbering

Physical GPU socket	Slot numbering in XCC	Logical number in nvidia-smi
GPU 1	Slot 21	4
GPU 2	Slot 24	7
GPU 3	Slot 22	5
GPU 4	Slot 23	6
GPU 5	Slot 17	0
GPU 6	Slot 20	3
GPU 7	Slot 18	1
GPU 8	Slot 19	2

The following illustration shows the components for front B200 GPU cold plate module.

Figure 2. Front B200 GPU cold plate module components identification

Table 1. Front B200 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 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. If rear B200 GPU cold plate module is already installed in the chassis, proceed with step 5 to 7 to reposition the rear cold plate manifold to create space for front cold plate module replacement. Skip step 5 to 7 if rear cold plate module is not installed yet.
5. Reposition the rear B200 GPU cold plate manifold to create space for front B200 GPU. Install the two service brackets onto the rear GPU cold plates.
   1. Align the guide pins on the service bracket with the guide holes on the GPU cold plate; then, lower it onto the cold plate.
   2. Fasten the two captive screws (PH1, 2 x M3, 0.5 newton-meters, 4.3 inch-pound) to install the service bracket onto the rear GPU cold plate. Repeat to install another service bracket.
      Figure 5. Installing the service brackets to the rear GPU cold plates
      
      

      Note

      Avoid pinching the leakage sensor module cable when installing the bracket.
      
      
6. Unfasten the four M3 screws (W7-W8) that secure the rear B200 GPU cold plate module manifold to the chassis.
   Figure 6. Removing the rear B200 GPU cold plate module manifold
   
   
7. Reposition the rear B200 GPU cold plate module manifold.
   1. Flip over the rear B200 GPU cold plate module manifold as illustrated. Align and insert the guide pins on the manifold into the guide slots on the shipping brackets; then, engage the manifold to the service brackets.
   2. Ensure the guide pins on the manifold are securely engaged with the guide slots on the shipping brackets.
      Figure 7. Repositioning the rear GPU cold plate module manifold
      
      
8. Loosen the screws by 360 degrees following the screw sequence: specified on the cold plate label, and fully loosen the sixteen Torx T15 screws with a torque screwdriver set to the proper torque.
   Note

   • Loosen the screws with a torque screwdriver set to the proper torque. For reference, the torque required for the screws to be fully loosen is 5.3±0.212 inch-pounds, 0.6±0.024 newton-meters.
   • Ensure the captive screws are completely loosen before removing the cold plate module.
   • Make sure to follow screw sequence to prevent cold plate tilting.
   Figure 8. Removing the GPU cold plates
   
   

   Note

   • If necessary, use the Tim breaker screw to separate the cold plate from the GPU. Ensure to fully loosen all the cold plate screws before fastening the TIM breaker screw.

     • Open the lid of the TIM breaker screw.
       
       
     • Fasten the TIM breaker screw to separate the cold plate from the GPU.
       
       

   • After usage, return the TIM breaker screw to its original position.

     • Loosen the TIM breaker screw to return it to its initial position.
       
       
     • Close the lid. If the lid cannot be closed, the TIM breaker screw needs to be further loosened.
       
       
9. Install the shipping brackets.
   1. Remove the crossbar before installing the shipping brackets. Unfasten the four captive screws to remove the crossbar.
      Figure 9. Removing crossbar
      
      
   2. Align the guide pins on the shipping brackets with the guide holes on the manifold and the cold plates; then, lower the shipping brackets onto the front B200 GPU cold plate module.
   3. Tighten the ten captive screws (PH1, 10 x M3, 0.5 newton-meters, 4.3 inch-pounds) to secure the shipping bracket to the front B200 GPU cold plate module. Repeat to install the other shipping bracket.
      Figure 10. Installing the shipping brackets
      
      

      Note

      Avoid pinching the leakage sensor module cable when installing the bracket.
      
      
   4. Reinstall the crossbar. Align the crossbar to the shipping brackets; then, fasten the four captive screws to install the crossbar to the shipping brackets.
      Figure 11. Installing the crossbar
      
      
10. Unfasten the four M3 screws (W5-W6) that secure the front B200 GPU cold plate module manifold to the chassis.
    Figure 12. Removing the front B200 GPU cold plate module manifold
    
    
11. Remove the front B200 GPU cold plate module.
    1. Release the hoses from the hose ties that secure them to the hose guides.
    2. Secure the hoses to the shipping brackets with the hose ties on the shipping brackets.
    3. Secure the leakage sensor module cable with the cable clip on the manifold.
    4. Hold the shipping brackets and lift the front B200 GPU cold plate module out of the chassis.
       Figure 13. Removing the front B200 GPU cold plate module
       
       

       Note

       If the cold plate screws are not fully loosened, use the Torx T15 screwdriver to fully loosen all the cold plate screws. Attach the Torx T15 200mm extension bit to reach the cold plate screws if necessary.
12. Immediately clean the PCM and putty pads off from the GPUs with alcohol cleaning pads. Gently clean the PCM and putty pads to avoid GPU damage.
    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 14. Cleaning PCM and putty pads off from the GPUs
    
    
13. With alcohol cleaning pads, wipe off any remaining putty pad and PCMs from the GPU cold plate module.
    Note

    Keep the shipping bracket attached to the cold plate module if it is to be reinstalled later.

    Figure 15. Wiping PCM and putty pads off from the cold plates