HP 70908A, Service Manual

Page: 297 / 335

A9 2nd Converter PLL
CA UTION
This module contains components that can be damaged or destroyed by
electrostatic discharge . It should be serviced at a static-safe workstation.
(Refer to \Preparing a Static-Safe W ork Station " in Chapter 4.)
T o Remove the A9 2nd Converter PLL
1. Remove the module cover . (Refer to the \Module Cover " procedure .)
2. Disconnect W6 (1) from A9J2.
3. Disconnect W5 (2) from A9J1.
4. Remove the four screws (3) and remove the 2nd converter cover .
5. Remove the two screws (4) and lift up the A9 2nd converter PLL (5).
6. Remove the cover (6) from the back of A9 2nd converter PLL.
T o Replace the A9 2nd Converter PLL
1. P osition the A9 2nd converter PLL over the V CO cover (6) with the notch (7) in the V CO
cover lined up with the notch in A9 2nd converter PLL .
2. Line up the feedthrough pins with the holes in A9 2nd converter PLL and press
A9 2nd converter PLL into place on the V CO cover .
3. Check that the V CO cover has RFI gasket strips (8) in its bottom slots .
4. Check that the D-shaped RFI gasket (9) on A9J1 is at-side up .
5. P osition the A9 2nd converter PLL/V CO cover in the module and replace the
two screws (4).
6. Check that the 2nd converter cover has RFI gasket strips (10) in all of its bottom slots .
7. P osition the 2nd converter cover over the A9 2nd converter PLL and replace the
four screws (3).
8. Reconnect W5 (2) to A9J1.
9. Reconnect W6 (1) to A9J2 so wire colors match silkscreen on the cover .
10. Replace the module cover . (Refer to the \Module Cover" procedure .)
9-30 Replacing Major Assemblies