Install the NVLink interposer board

Use this information to install the NVLink interposer board.

Procedure

1. There are two P12V middle bus bars in the tray, the left-side bus bar and right-side bus bar. Remove and loosen the screws from the bus bar according to the table below. Decide which bus bar is to be removed, and remove and loosen screws according to the table and illustration below.

   1 Right-side bus bar: 1a Remove two (2x) PH1 screws 1b Loosen four (4x) T15 thumb screws

   2 Left-side bus bar: 2a Remove one (1x) PH1 screws 2b Loosen four (4x) T15 thumb screws

   Figure 1. P12V middle bus bar screws
   
   

   Figure 2. Removing and loosening screws on the right-side bus bar
   
   

   Figure 3. Removing and loosening screws on the left-side bus bar
   
   
2. Remove the eight (8x) screws from the P12V front bus bars.
   Figure 4. Removing P12V front bus bar screws
   
   
3. Remove the P12V middle bus bars from the tray.
   1. Remove the right-side bus bar.
   2. Remove the left-side bus bar.
   Attention

   • Make sure to follow the bus bar removal sequence: Right-side bus bar > Left-side bus bar

   • Pay extra attention and care when moving the P12V middle bus bar. Make sure the bus bar does not hit the connectors on the GB200-NVL4 board.

     Figure 5. Prevent P12V middle bus bar hitting the connectors on GB200-NVL4 board
     
     

   Figure 6. Removing the right-side bus bar
   
   

   Figure 7. Removing the left-side bus bar
   
   
4. Loosen eight (8x) T10 thumbscrews from the two GB200-NVL4 boards, as shown in the illustration below.
   Figure 8. Loosening eight thumb screws from GB200-NVL4 boards
   
   
5. Fasten only two (2x) T10 thumbscrews on the GB200-NVL4 boards (one thumb screw for each board), as shown in the illustration below.
   Note

   For reference, the torque required for the screws to be fully tightened/removed is 5.0+/- 0.5 in-lbs, or 0.55+/- 0.05 m.

   Figure 9. Fastening two thumb screws on the GB200-BVL4 boards
   
   
6. Align the NVLink interposer board to the guide flanges on the tray; then, gently attach the NVLink interposer board to the GB200-NVL4 boards.
   Figure 10. Installing NVLink interposer board
   
   
7. Move the NVLink interposer board installation fixture above the tray. Align the fixture with the four (4x) guide pins on the tray; then, place down the fixture to the tray.
   Figure 11. Install the NVLink interposer board installation fixture to the tray
   
   
8. Install four (4x) screws to secure the fixture to the tray.
   Figure 12. Securing the fixture to the tray
   
   
9. Rotate the fixture handle to push the NVLink interposer board forward to connect to GB200-NVL4 boards.
   Figure 13. Rotating the fixture handle
   
   
10. Install six (6x) screws to secure the NVLink interposer board stiffeners.
    Note

    The stiffener are directional. Make sure to place them as oriented as shown in the illustration below.

    Figure 14. Installing the NVLink interposer board stiffeners
    
    
11. Install the cable tie to the stiffeners.
    Figure 15. Installing cable tie
    
    
12. Install the screws to secure the NVLink interposer board to the GB200-NVL4 boards.
    Note

    Install the twelve (12x) screws with a two-phase manner. First, fasten the screws with a torque screwdriver set to 1. 0+/- 0.5 in-lbs. Then, fasten the screws with a torque screwdriver set to 5. 0+/- 0.5 in-lbs.

    Figure 16. Installing the NVLink interposer board
    
    
13. Fasten eight (8x) T10 thumb screws to install the GB200-NVL4 boards to the tray.
    Note

    For reference, the torque required for the screws to be fully tightened/removed is 5.0+/- 0.5 in-lbs, or 0.55+/- 0.05 N-m.

    Figure 17. Fastening eight screws to install GB200-NVL4 boards
    
    
14. Align the P12V middle bus bars to slots on the P12V front bus bar. Then, slide the P12V middle bus bar into the slots to install it to the tray.
    1. Install the left-side bus bar.
    2. Install the right-side bus bar.
    Attention

    • Make sure to follow the bus bar installation sequence: Left-side bus bar > Right-side bus bar

    • Pay extra attention and care when moving the P12V middle bus bar. Make sure the bus bar does not hit the connectors on the GB200-NVL4 board.

      Figure 18. Prevent P12V middle bus bar hitting the connectors on GB200-NVL4 board
      
      

    Figure 19. Installing left-side P12V middle bus bar
    
    

    Figure 20. Installing right-side P12V middle bus bar
    
    
15. Install and fasten screws to secure the bus bar according to the table below.

    1a Install two (2x) PH1 screws, on right-side bus bar 2a Install one (1x) PH1 screws, on left-side bus bar Install the screws with a torque screwdriver set to 5.0 +/- 0.5 in-lbs, or 0.56 +/- 0.056 N-m.

    1b Fasten four (4x) T15 thumb screws, on right-side bus bar 2b Fasten four (4x) T15 thumb screws, on left-side bus bar First, install the screws with a torque screwdriver set to 1.5 in-lbs, or 0.169 N-m. Then, set the torque screwdriver to 17.5 in-lbs, or 1.977 N-m, and tighten the screws again.

    Figure 21. Installing screws on the P12V middle bus bars
    
    

    Figure 22. Installing screws on the right-side bus bar
    
    

    Figure 23. Installing screws on the left-side bus bar
    
    
16. With a torque screwdriver set to the proper torque, install the eight (8x) T30 screws to the P12V front bus bars.
    Note

    For reference, the torque required for the screws to be fully tightened/removed is 15.0 +/- 0.5 in-lbs, or 1.69 +/- 0.056 N-m.

    Figure 24. Installing P12V front bus bar screws