R&S ZVA8, Руководство по обслуживанию

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Repairs R&S ZVA
1177.5333.02 3.54 E-11
Replacing Motherboard A10
(See Chapter 5, Spare Parts List, Item 510 and drawings 1145.1110, 1145.1310)
The motherboard is located on the base of the instrument.
N.B.: The motherboard can only be replaced at R&S service centers.
Opening the instrument and removing the motherboard

Turn off the instrument and disconnect from the mains, screw off the 4 rear-panel feet (460) and
pull off the enclosure (400) backwards.

Lift off the top instrument cover (296) after undoing the countersunk screws (298).

Extract the top boards: Use ejector lever for the synthesizer and network controller, hold the
frequency reference by the enclosure.

Remove the power supply (550).

Remove the 4 screws (757) in the rear panel.

Pull out the power supply unit a little at the rear of the instrument, remove screw (737) and anti-
touch guard (736).

On the left-hand side of the power supply, pull off the protective conductor cable and the fuse
board (735) to the left.

On the right-hand side of the power supply, pull off the plug-in connections to the motherboard.

Remove the power supply unit.

Remove the 4 screws in the front handles (410), right and left, 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 termination and 3.5mm connection cables (only with option ZVAx-B16)

Remove the 2 countersunk screws (610) in the top of the front frame and the 2 in the bottom.

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 to the front module controller.