Start Troubleshooting Here - Agilent Technologies 8719ET Service Manual

8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers

Start Troubleshooting Here

1. Make sure all of the assemblies are firmly seated.
2. Verify that the analog bus is working by pressing the following:
SERVICE MENU
System
• If the analyzer fails the test, return to
• If the test passes, continue with this section.
3. Make sure that input R has a signal of at least −35 dBm (about 0.01 Vp-p into 50 ohms)
at all times to maintain phase lock. To make this measurement, perform the following
steps:
a. Perform steps 1 and 2 of
page 3-6. Make note of the DAC number that is displayed and then abort the
procedure.
b. Press the following:
SERVICE MENU
System
DAC NUM HIGH BAND
c. Enter the DAC number determined from step 3a and press
d. Zero and calibrate a power meter.
e. For ET analyzers:
On ET models, there are two ways to measure the R-channel sampler assembly
power.
1. Remove the bottom cover and disconnect the semirigid cable (W74) to the
RF INPUT (J2) of the R-channel sampler. Connect a 2.4 mm (f) barrel, flexible
cable, and the power sensor to W74.
CAUTION Be careful not to damage the center pins of the semirigid cable. Some flexing
of the cable will have to be done to attach the power sensor. Do not over bend
the cable.
2. Remove the front panel and disconnect the junction between the cables W72 and
W74. Connect the power sensor to W72.
• If the power level is at least −35 dBm, proceed to
Displayed" on page
• If the power level is lower, proceed to
page 7-6.
Service Guide
TESTS
19 x1
"Step 4. Faulty Group Isolation" on page
"Source Pretune Correction Constants (Test 43)" on
SERVICE MODES
7-6.
"Power Not within Specifications" on
Start Troubleshooting Here
EXECUTE TEST
SRC ADJUST MENU
.
x1
"Phase Lock Error Message
Source Troubleshooting
4-13.
7- 5