Compaq Prolinea Family Maintenance & Serice Manual page 130

Note the orientation of the notched corner of the processor and reverse
the above procedure to install a processor.
Chapter 5.17 Cache Board
This procedure applies to 486-based system boards only. The secondary
cache board is installed on the 486-based system board adjacent to the
SIMM sockets (Figure 5-47).
the following steps:
1. Complete the steps in Section 5.3 to prepare the computer for
disassembly.
2. Complete the steps in Unit Cover Removal and Replacement in Section 5.4
to gain access to the system board.
3. Remove any option or expansion cards (Sections 5.11 and 5.13) that
interfere with access to the cache board.
4. Remove the secondary cache board as shown in Figure 5-49.
To remove the secondary cache board, complete