Replacing the SAN Volume Controller 2145-8A4 microprocessor

This topic describes how to replace the microprocessor.

1. Make sure that the microprocessor bracket frame  and release latch , shown in Figure 1, are both fully open.
   Attention:

   • The microprocessor contacts are fragile; handle the microprocessor very carefully. Do not touch the microprocessor contacts with your skin.
   • The microprocessor fits only one way on the socket.
   Figure 1. SAN Volume Controller 2145-8A4 microprocessor

   
2. Align the microprocessor with the socket as shown in Figure 1. (Note the alignment mark  and the position of the notches .)

   Then, carefully place the microprocessor on the socket, close the microprocessor bracket frame , and close the microprocessor release latch .

3. Install the heat-exchanger assembly.
   • If you are installing a new heat-exchanger assembly, peel off the protective backing from the thermal material that is on the underside of the new heat exchanger.
   • If you are reinstalling a heat-exchanger assembly that was previously removed, replace the contaminated or missing thermal grease:
     1. Place the heat-exchanger assembly on a clean work surface.
     2. Remove the cleaning pad from its package and unfold it completely.
     3. Use the cleaning pad to wipe the thermal grease from the bottom of the heat exchanger. Make sure that all of the thermal grease is removed.
     4. Apply thermal grease to the top of the microprocessor, as shown in Figure 2. Apply nine dots of thermal grease in three rows of three dots each with the outer rows approximately 5 mm from the edge of the microprocessor. The diameter of the cap from the thermal grease syringe is 5 mm, so you can use it to judge the required position of the dots of thermal grease
        Note: 0.01mL is one tick mark on the syringe. If the grease is properly applied, approximately half (0.22 mL) of the grease will remain in the syringe.
        Figure 2. Complete set of nine thermal grease dots on the SAN Volume Controller 2145-8A4 microprocessor

        
4. Make sure that the heat-exchanger assembly release latch is fully opened.
5. With the heat-exchanger assembly at an angle, carefully align the heat-exchanger assembly with the microprocessor and the heat exchanger retention module (socket) on the system board. Make sure that the alignment pins , shown in Figure 3, protrude through the alignment hole (the opening in the side of the heat-exchanger bracket) and that the flange of the heat sink rests under the lip of the heat-exchanger socket.
   Figure 3. Alignment pins on the SAN Volume Controller 2145-8A4 heat-exchanger assembly

   
6. Gently press the assembly into place.
7. Close the heat-exchanger-assembly release latch, catching it under the hook on the socket.
8. Replace the air baffle. Align the air baffle and then press the air baffle into position until it clicks into place.
9. Replace the top cover. See Replacing the top cover.
   
10. Place the node in the rack. See Replacing the SAN Volume Controller in a rack.
    
11. Reconnect the power cords and any cables that were removed.
12. Turn on the node.