R&S ZVA24, Service Manual

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Repairs R&S ZVA
1177.5333.02 3.80 E-11
Troubleshooting - Power-up Problems

Fault: It is not possible to turn on the ZVA.
Action Cause of fault / remedy
Check mains switch on the rear panel

Mains switch OFF: Turn on at mains switch.
Check LED is yellow (standby)

LED does not come on:

Measure voltage at X92.C23
(Front module controller):
Nom. value: +13.5 V

1V
Nom. value reached: Fault in key pad or controller.
No voltage:
Power supply defective or short to12 V standby.
Turn on instrument. Check LED is green

LED does not come on:

Measure the PWR-ON signal at power supply
X92.B24:
< 1V for ON
Voltage > 1V: Key pad or controller defective.

Fault: Fan not working.
Action Cause of fault / remedy
Check voltage at connector:
X35, X36, X37 pin 3:
nom. value 12V

If no voltage can be measured the fan fuse may be
defective (F12, F62, F63)
Select Service Function
Set Service Level 1
Set Service Function 2.5.0.11.1.5
(max. fan speed)
Check voltage at connector:
X35, X36, X37 pin 3:
nom. value 0.9V