Agilent Technologies E4440A, Service Manual

Page: 384 / 436

384 Chapter 11
Assembly Replacement Procedures
A25 Motherboard
Replacement
1. Refer to Figure 11-45 on page 379 . Place the motherboard into
position in the deck. Using the T-10 driver, replace the screws that
secure the mother board to the deck. For alignment purposes,
tighten the screws in the order marked on the motherboard #1 and
#2 first, then tighten the #3, #4, and #5 screws. Torque to 9 inch
pounds.
2. Using the T-10 driver, replace the 6 screws on the bottom of the
instrument as indicated in Figure 11-47 . Torque to 9 inch pounds.
3. Reattach the W10 flat flex cable and W8 ribbon cable to the
motherboard.
4. Replace the mid-web/fan assembly. Refer to the “Fans/Mid Web”
replacement procedure.
5. Replace the A5 assembly. Refer to the “A5 Power Supply”
replacement procedure.
6. Replace the A26 assembly. Refer to the “A26 CPU Assembly”
replacement procedure.
7. Replace the RF section. Refer to the “RF Section E4440A, E4443A,
E4445A” replacement procedure.
8. Replace the vertical assemblies. Refer to the “Vertical Board
Assemblies (Standard Instrument)” replacement procedure.
9. Replace the attenuator assembly. Refer to the “Attenuator Assembly
E4440A, E4443A, E4445A” replacement procedure.
10.Replace the front frame assembly. Refer to the “Front Frame”
replacement procedure.
11.Replace the instrument top brace. Refer to the “Top Brace”
replacement procedure.