R&S ZVA8 - Replacing the Reflectometers on ZVA80

Repairs R&S ZVA
1177.5333.02 3.66 E-11
Replacing the Reflectometers on ZVA80-BU
Port1 and port2: See Replacing a Reflectometer RM 40 and RM50
Port3 and port4:
(See Chapter 5, drawing 1312.6508)
(See Chapter 5, Spare Parts List, Item 100, and drawing 1166.1660)
The boards are located under the motherboard.
Opening the instrument and removing the board
 Turn off the instrument and disconnect from the mains, screw off the 4 rear-panel feet (460) and
four screws (455), remove the two side handles (450) and pull off the enclosure (400) backwards.
 Remove the 4 screws in the front handles (410), right and left, and take off the front handles.
 Remove the countersunk screw (315) and pull off the front cover (300) forwards
 Remove the bottom instrument cover (298) after undoing the 18 countersunk screws (299).
 Remove RF connection cables (ZVA50-B16)
 Disconnect the source cable, the LO cable, the two IF cables and the 50-pin control cable from the
reflectometer.
 Remove the 4 screws (3132) and the 2 screws (3133) in the front of the instrument next to the port
connector.
 Remove the 5 screws (3131) and take out the reflectometer
Installing the board and reassembling the instrument
 Insert the new board into the instrument and reconnect any cables that have been disconnected.
N.B.: Use the lettering on the motherboard as an aid.
 Screw in the 6 screws (3132, 3133) in the front of the instrument next to the port connector.
 Screw in the 5 screws (3131).
 Refit support plates (3140, 3142) and reflectometers A530, A540, A560 (only with option ZVT20-
B63, -B64, -B66).
 Fit the instrument base cover (298) and secure with 18 countersunk screws (299).
 Replace the front cover (300) and secure with the countersunk screw (315).
 Refit the 2 front handles (410) using 4 screws.
 Slide the enclosure (400) back on and screw the 4 rear-panel feet (460) and the 2 side handles
(450) into position.
 Connect the mains cable and turn on at the mains switch. The instrument is now in the standby
mode
 Select Service Level 2 (see Service Functions).
 When the instrument has been started, check the protocol file for errors:
[ INFO : Error Log ]
 Record the generator and receiver correction data (see Recording Correction Values).
 Perform the factory system error calibration (see Factory System Error Calibration).