Remove a CX8 mezzanine module

Use this information to remove a CX8 mezzanine module.

Procedure

1. Make preparations for this task.
   1. Remove the tray from the enclosure. See Remove a tray from the enclosure.
   2. Remove the tray cover. See Remove the tray cover.
   3. Remove the cross bar. See Remove the cross bar.
   4. Disconnect all the cables from the GB200-NVL4 board. See Internal cable routing.
2. Acquire the OSFP adapter cable connector covers.
   1. Open the in-tray tool box.
   2. Take out the cable connector covers. Take out two covers when removing one CX8 mezzanine module; four covers if removing two CX8 mezzanine modules.
   Figure 1. Acquiring OSFP adapter cable connector covers
   
   
3. Acquire the OSFP adapter cable removal tool.
   1. Open the in-tray tool box.
   2. Take out the cable removal tool.
   Figure 2. Acquiring CX8 mezzanine module cable removal tool
   
   
4. Acquire the OSFP sideband cable holder.
   1. Open the in-tray tool box.
   2. Take out the cable holder.
   Figure 3. Acquiring OSFP sideband cable holder
   
   
5. Remove the cable retainer from the CX8 mezzanine module.
   1. Remove two T15 screws from the CX8 mezzanine module.
   2. Remove the cable retainer from the CX8 mezzanine module.
   Note

   For reference, the torque required for the screws to be fully tightened/removed is 5.0+/- 0.5 in-lbs, 0.55+/- 0.056 N-m.

   Figure 4. Removing the cable retainer on the CX8 mezzanine module
   
   
6. Disconnect the OSFP adapter cables from the CX8 mezzanine module. Use the cable removal tool acquired in Step 3.
   1. Pinch the latch on the tool.
   2. While pinching the latch, insert the tool into the cable connector.
   3. Release the latch. Hold the tool; then, lift up the cable connector.
      Figure 5. Disconnecting the OSFP cable
      
      
7. Take the covers acquired in Step 2 and install the covers to all the OSFP adapter cables.
   Figure 6. Installing covers to the OSFP adapter cables
   
   
8. Take the cable holder acquired in Step 4, and install the cable holder to the OSFP sideband cable that is connected to the CX8 mezzanine module.
   Figure 7. Installing cable holder to the OSFP sideband cable
   
   
9. Disconnect the OSFP sideband cable.
   Figure 8. Disconnecting OSFP sideband cable
   
   
10. There are two P12V middle bus bars in the tray, the right-side bus bar and the left-side bus bar. Decide which bus bar is to be removed, and remove and loosen screws according to the table and illustration below.
    Attention

    • When removing the right-side CX8 mezzanine module: remove the right-side bus bar.

    • When removing the left-side CX8 mezzanine module: remove the right-side bus bar; then, remove the left-side bus bar.

    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 9. P12V middle bus bar screws
    
    

    Figure 10. Removing and loosening screws on the right-side bus bar
    
    

    Figure 11. Removing and loosening screws on the left-side bus bar
    
    
11. Remove the eight (8x) screws from the P12V front bus bars.
    Figure 12. Removing P12V front bus bar screws
    
    
12. Remove the P12V middle bus bar according to which CX8 mezzanine module is to be removed.
    Attention

    • When removing the right-side CX8 mezzanine module: remove the right-side bus bar.

    • When removing the left-side CX8 mezzanine module: remove the right-side bus bar; then, remove the left-side bus bar.

    Figure 13. Removing the right-side bus bar
    
    

    Figure 14. Removing the left-side bus bar
    
    
13. Install the cross bar to the front of the tray.
    1. Align the cross bar with the screw holes on the tray side walls; then, install it to the tray.
    2. Install four (4x) screws to secure the cross bar to the tray.
    Figure 15. Installing cross bar to front of the tray
    
    
14. Install the GPU cold plate handle to the GB200-NVL4 board to be removed.
    Figure 16. Installing GPU cold plate handle to the water loop
    
    
15. Fasten eight (8x) thumbscrews to install the GPU cold plate handle. Make sure to follow the sequence shown in the illustration below.
    Figure 17. Fastening GPU cold plate handle screws
    
    
16. Lock the retaining thumbscrew on the GPU cold plate handle.
    1. Loosen the nut.
    2. Remove the nut and the washer from the GPU cold plate.
    3. Push the screw into the slot
    4. Re-install the nut and washer back to the GPU cold plate.
    5. Fasten the nut to the screw to secure handle to the GPU cold plate.
       Figure 18. Locking the retaining thumb screw
       
       
17. Install the T15 extension bit to the torque screwdriver; then, loosen twenty-one (21x) T15 thumbscrews to release the GPU cold plate from the GB200-NVL4 board. Make sure to follow the sequence shown in the illustration below.

    • Screw 16, 17, 18, 19, 20, 21 are ONLY for Dual CX8 mezzanine module configuration. Fasten/loosen fifteen (15x) screws for MCIO breakout board.

    • Installing the T15 extension bit to the torque screwdriver before loosening the screws.

      Figure 19. T15 extension bit
      
      

    Figure 20. Loosening GPU cold plate screws
    
    
18. Install the GPU cold plate to the cross bar.
    1. Flip the GPU cold plate and place it on the cross bar.
    2. Fasten two (2x) PH2 thumb screws to secure the GPU cold plate to the cross bar.
    Figure 21. Install right-side GPU cold plate to the cross bar
    
    

    Figure 22. Install left-side GPU cold plate to the cross bar
    
    
19. Remove the CX8 mezzanine module.
    1. Follow the sequence shown in the illustration to unfasten four T15 thumb screws. The removal sequence is > > >
    2. Remove the mezzanine module from the tray.
    Figure 23. Removing the CX8 mezzanine module