R&S ZVA24, Service Manual

Page: 391 / 606

R&S ZVA Repairs
1177.5333.02 3.83 E-11
Troubleshooting with the Selftest
The selftest is used to check supply voltages to the boards, including voltages generated on the boards
themselves. On the frequency reference board, two clock signals (128 MHz and ADC-CLK) are also
measured.
Starting the selftest:

Select Service Level 2 (see Service Functions)
– this means that the temperature sensor readings
are displayed and tighter voltage tolerances used.

Call the selftest in the INFO menu:
Start the selftest with the Selftest softkey.
The selftest results are displayed on the
screen.
In the selftest result-table, an abbreviation is used for every board designation:
Fr
Frequency reference
Nd1
Network controller1, digital section
Nd2
Network controller2, digital section (only 4-oort instruments)
Sy1/DDSCON
Synthesizer1
Sy1/DDSCON
Synthesizer2(only 3-port and 4-port instruments)
Rm1
Reflectometer port1
Rm2
Reflectometer port2
Rm3
Reflectometer port3 (applies only to 3-port and 4-port-instruments)
Rm4
Reflectometer port4 (applies only to 4-port instruments)