R&S ZVA24, Service Manual

Page: 336 / 606

Repairs R&S ZVA
1177.5333.02 3.28 E-11
Replacing Front Module Controller A90
(See Chapter 5, Spare Parts List, Item 580, and drawings 1145.1110, 1145.1310)
The front module controller is located behind the front unit.
Opening the instrument and removing the front unit

Turn off the instrument and disconnect from the mains.

Remove termination and 3.5mm connection cables (only with option ZVAx-B16)

Remove the 4 screws from the front handles (410), left and right, and take off the front handles.

Remove the countersunk screw (390) next to the display and pull off the front cover (300, 303, 306,
310, 313, 316) forwards

Remove the 2 countersunk screws (610) in the top of the front frame and the 2 in the bottom.

ZVA8: Remove the countersunk screws (168) (2 ), (153), (154), (163), (164)

Pull out the front unit together with the keyboard and display (600, 604) forwards.
Risk of damage
The cables to the front module controller are still connected.

Disconnect the cables to the LCD, the DC/AC illumination converter, the key pad (keyboard), the
tachogenerator and, if necessary, the network connection on the front module controller.
Risk of damage
When disconnecting cables, be especially careful with the cable to the keyboard. It is a
foil cable and can only be removed when the locking device on the foil-cable connector
is released.
Removing the front module controller

Remove the 10 sems screws (590) in the front module controller and remove the front module
controller in the following way (see Fig. 3-5):
Note:
The insertion force for the front module controller on the motherboard is very large.
The slot in the bottom of the controller tray is provided to facilitate pushing out the front module
controller forwards.
Using a blunt, flat tool, carefully edge the board forwards.