Remove the power distribution board

Use this information to remove the power distribution board.

Procedure

1. Make preparations for this task.
   1. Remove the tray from the enclosure. See Remove a DWC tray from the enclosure.
   2. Remove the tray cover. See Remove the tray cover.
   3. Remove the cross braces. See Remove the cross braces.
   4. Remove the DIMM comb. See Remove a DIMM comb.
   5. Remove memory modules. See Remove a memory module.
   6. Remove the M.2 backplane assembly. See Remove the M.2 backplane assembly.
      Note

      The M.2 backplane cold plate needs to be removed as well.
   7. Remove the bus bar. See Remove the bus bar.
   8. Remove the MCIO cables. Follow the guidance and routing information in Internal cable routing.
   9. Remove the drive cage. See Remove a drive cage assembly.
   10. Remove the OSFP module. See Remove the OSFP module.
2. Remove the two Hex screws from the OSFP module with a 4.5 mm hex head screwdriver.
   Figure 1. OSFP module conduction plate Hex screws removal
   
   
3. Remove the OSFP module conduction plate. With alcohol cleaning pads, wipe of any remaining putty pads from the conduction plate.

   Screw Type	Screwdriver Type
   1 M3x5 screw (x3)	Phillips #1 head screwdriver
   2 M3 screw (x2)	T10 screwdriver

   Figure 2. OSFP module conduction plate removal
   
   
4. Remove the five Torx T10 screws to loosen the quick connect.
   Note

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

   Figure 3. Quick connect screw removal (Compute node)
   
   
5. Remove water loop screws and quick connect screws (14x Torx T10 screws per node) with a torque screwdriver set to the proper torque.
   Note

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

   • When removing the 1 VR cold plate screws (x2), remove the washers, too. Make sure to keep the washers for future use.

     Figure 4. VR cold plate screws with washer
     
     

   Figure 5. Water loop screw removal

   1 VR cold plate screws (x2)

   
   
6. Remove processor cold plate screws (12x Torx T20 screws per node). Follow the screw sequence specified on the processor cold plate label and loosen the screws with a general screwdriver. Fully loosen each screw; then, proceed to the next screw.
   Note

   For reference, the torque required for the screws to be fully tightened/removed is 1.12-1.46 newton-meters, 10-13 inch-pounds

   Figure 6. Processor cold plate label

   Fully loosen each screw in this order: 6 > 5 > 4 > 3 > 2 > 1

   
   
   

   Figure 7. Processor cold plate removal
   
   
7. Orient the water loop carrier with the guide pin; then, gently put the water loop carrier down and ensure it is seated firmly on the water loop.
   Figure 8. Water loop carrier installation (Compute node)
   
   
8. Tighten water loop carrier screws (x12 Phillips #2 screws).
   Note

   Select screw holes marked as R on the rear of the shipping bracket.

   Figure 9. Water loop carrier screws installation (Compute node)
   
   
9. Rotate the latch on the water loop carrier to separate the water loop from processors.
   Figure 10. Separate water loop from processor
   
   
10. Carefully rotate the water loop so one half is sitting on top of the other half.
    Figure 11. Folding the water loop
    
    
11. Remove the power distribution board.
    1. Remove the five M3 screws (per node) with a 3/16" hex head screwdriver.
    2. Gently pull the power distribution board connector to disconnect it from the system board.
    3. Carefully pull the power distribution board inwards to disengage it from the node.
    Note

    Use a 3/16" hex head screwdriver to ensure the proper removal and installation.

    Figure 12. Power distribution board removal
    
    
12. With an alcohol cleaning pad, wipe off any remaining thermal grease, gap pads, and putty pads from the processor and water loop.