Troubleshooting Using Diagnostics Test; Power On Self Test; Pll Unlock; External Reference Signal Phase Unlock (Opt. 1E5) - Agilent Technologies E5071C Service Manual

Troubleshooting

Troubleshooting Using Diagnostics Test

Troubleshooting Using Diagnostics Test
The Agilent E5071C has the diagnostics test function to diagnose the analog measurement
section and internal dc power supply voltages. The diagnostics test makes it possible to
isolate a faulty board assembly without need of external test equipment. The following
paragraphs describe the procedure to perform the internal test.

Power On Self Test

Power-on self-test always takes place once after the E5071C is turned on. When a failure is
detected, a message of the "Power on self test failed" is displayed. The content of the
power-on self-test is the same as a portion of the siagnostics test program and includes the
dc power supply voltage, source PLL synthesizer and level controller (ALC) tests. When
the self-test failed, perform the diagnostics test to break down into the individual tests and
narrow down failure possibilities.
NOTE The following procedure can be used to restart the power-on self test as required.
a. Press
b. Click
c. Click
d. The test result (OK or Failed) is displayed in the

PLL unlock

When a PLL of the frequency synthesizers is unlocked, not the "Power on self test failed"
but "Phase lock loop unlocked" message is displayed. If it occurs, Synthesizer Module may
be faulty.

External reference signal phase unlock (Opt. 1E5)

If the "ExtRef" in the instrument status bar is displayed in gray, not turning blue, in using
the high stability time base (Opt. 1E5), Crystal Oven board or the interconnection cable
between rear panel Ref Oven and Ref In connectors may be faulty. Also check whether the
"Ready" in the instrument status bar is displayed in blue (the warm-up in the instrument is
completed). If it is in gray, wait until the "Ready" turns blue.

Contents of the diagnostics test

The diagnostics test contains 7 test groups shown in Table 4-1. Each test group can be
performed independently and verifies one of various operating characteristics of the analog
measurement section.
Table 4-1
186
key.
and, then,
Service Menu Test Menu
to restart the test. Wait until the power-on test ends.
Power On Test
Diagnostic test group menu
Number Test Name
1 DCBUS TEST
in the softkeys.
key.
Power On Test
Chapter 4