Fujitsu M255XK Customer Engineering Manual page 66

4.5.6 Main Circuit Card Replacement
Tools Required: Phillips Screwdriver, M3
Refer to Figure 5-5.
1.
Remove the shield cover (item 44).
2. Remove the mounting screws from the main circuit card and lift up the
circuit card (item 43), unplug all connectors at the main circuit card assembly
and remove the card.
3. Remove the screws holding the main circuit card shield plate and remove the
plate (item 23).
4. Install a new main circuit card assembly by reversing the removal procedure
given above in steps 2 and 3.
Note: The Main Circuit Card is available at different revision levels, obtain the
correct Drawing Number from the replaced circuit card.
5. Set the circuit card selection jumpers in the same positions as they were on
the removed card (refer to Figure 4-1, Table 4-5).
6. Check asymmetry (paragraph 4.4.7).
7. Check read level (paragraph 4.4.8).
8. Check read resolution (paragraph 4.4.9).
9. Check Track 00 sensor (paragraph 4.4.11).
10. Replace the shield cover assembly.
11. Connect the disk drive to the system and perform an overall test.
4-34 TS-021-013087 ••• 01