Rohde & Schwarz 1164.4391.03, Service Manual

Page: 190 / 254

Troubleshooting R&S FSP
1164.4556.82 3.86 E-1
Normal action Error and error cause
Calibration signal level:
FATAL ERROR!
IF Board: CAL Signal level out of range for selftest
Selftest aborted.
The selftest of the signal path can not be
performed with failure of the calibration signal.
Switch on measurement via the INPUT CAL
softkey in the SETUP - SERVICE menu.
While attending this menu, the level can be
switched over between -30 dBm and 0 dBm
using the step keys
.
Measure the calibration signal at X142 of the
IF-filter board.
Option W-CDMA Demod. Hardware installed
Measure the calibration signal at X192 of the
W-CDMA Demodulation Hardware.
Control voltage of calibration signal:
ERROR!
IF Board: CAL Signal level control loop unlocked
As soon as the control voltage violates the
tolerance, the level control loop unlocks and the
level becomes inaccurate. If the level error is
small, the selftest of the signal path can be
performed. However, following the calibration of
the instrument, the level measuring accuracy will
be out of tolerance.
Prior to replacing the IF-filter board, check,
whether the level applied in X134 is between -4
and +6 dBm. The typical level range of the CAL
generator is -5 dBm to +8 dBm.
If the level is outside this range, the Frontend
Module 2 must be replaced.