Keysight Technologies N5221A, Service Manual, Page: 295 / 368

Keysight N5221A/22A Service Guide 7-31
Repair and Replacement Procedures
Removing and Replacing the A20 IF Multiplexer Board
Removing and Replacing the A20 IF Multiplexer Board
Tools Required
— T-10 TORX driver (torque to 9 in-lb or 1.02 N.m)
— T-20 TORX driver (torque to 21 in-lb or 2.38 N.m)
— 5/16 inch open-end torque wrench (torque to 10 in-lb or 1.13 N.m)
— ESD grounding wrist strap
Removal Procedure
Refer to Figure 7-13 for this procedure.
1. Disconnect the power cord.
2. Remove the outer cover. Refer to “Removing the Covers” on page 7-6 .
3. Position the analyzer bottom side up.
4. Remove the A19 test set motherboard. Refer to “Removing and Replacing
the A19 Test Set Motherboard” on page 7-29 .
5. Disconnect the ribbon cable (item
①
) from the A20 IF multiplexer board.
6. Disconnect ALL gray flexible RF cables (item
➁
) from the A20 IF
multiplexer board.
7. Remove connector hardware (item
③
) from five rear panel RF connectors.
8. Remove connector hardware (item
④
) from the rear panel PULSE I/O
connector.
9. Remove four screws (item
⑤
) from the stabilizer bracket and remove the
stabilizer bracket.
10. Remove four screws (item
⑥
) from the A20 IF multiplexer board.
11. Slide the A20 IF multiplexer board toward the front of the instrument until
the rear panel connectors are free of the rear panel, then lift the
multiplexer board and remove it from the analyzer.
Replacement Procedure
1. Reverse the order of the removal procedure.
Attach the stabilizer bracket to the new A20 IF multiplexer board using the
screws removed from the old one.
Torque rear panel RF connector nuts to 21 in-lbs and PULSE I/O connector
screws to 6 in-lbs.
2. Perform the post-repair adjustments, verifications, and performance tests
that pertain to this removal procedure. Refer to Table 7-2 on page 7-60 .