Keysight E8257D/67D - Page 61

E8257D/67D, E8663D PSG Signal Generators Service Guide
Troubleshooting
Troubleshooting Assembly–Level Problems
1-47
Before proceeding to the reported self–test error code, check the following voltages in. If any of these voltages are out
of specification, troubleshoot the supply problem first.
1200 Power Supply
1. Press View Test Info and highlight Self Test 1200. Press View Details.
2. From the displayed self–test results, determine which supply or supplies failed.
3. Refer to the following table; disconnect one microcircuit at a time and run self–test 1200.
• If the test passes after disconnecting one or more microcircuits, replace the microcircuit.
• If self–test still fails after disconnecting all the microcircuits, replace the A26 MID.
1201 Mod Filter
1. Disconnect the cable between the A23 Lowband Coupler/Detector and the A30 Modulation Filter, and connect a
spectrum analyzer to the cable.
2. Tune the source across the lowband frequencies (250 kHz to 3.2 GHz) and record the lowest power level.
3. Disconnect the cable coming from the A29 20 GHz Doubler, and connect the spectrum analyzer to this cable.
4. Tune the source across the A29 20 GHz Doubler band of frequencies (3.2 GHz to 20 GHz) and record the lowest
power level.
5. Determine the expected levels using the tools described in “Troubleshooting RF Power Levels” on page 1- 75, and
compare them to the measured levels.
• If the power level in both paths is good, replace the A30 Modulation Filter.
• If the power level in either path is bad, troubleshoot that path.
Supply
Volt age
(Vdc)
E8257D
Connector
Pins
All Other Models
Connector
Pins
Minimum
Value
(Vdc)
Maximum
Value
(Vdc)
Origin
+32 P201–11 P201–1 +31.04 +32.96 Main Supply
+15 P201–12, 13, 14 P201–2, 3, 4 +14.55 +15.45 Main Supply
–15 P201–21, 22 P201–11, 12 –15.45 –14.55 Main Supply
+5.2 P201–7, 8, 9, 10, 23, 24, 25,
26, 27, 28
P201–13, 14, 15, 16, 17,
18
+5.04 +5.36 Main Supply
+10 P201–15, 16, 17, 18, 19, 20 P201–5, 6, 7, 8, 9, 10 +9.7 +10.3 Main Supply
+8 P201–39 P201–29 +7.5 +8.5 MID
–7 P201–40, 43, 56 N/A –7.21 –6.79 Main Supply
–5.2 P201–41, 42 P201–31, 32 –5.30 –5.10 YIG Driver
+5.2 Digital high P201–33 P201–23 +5.04 +5.36 Main Supply
+3.4 Digital Low P201–34 P201–24 +3.3 +3.5 Main Supply
Microcircuit A26 MID
Connector
+12V +8V +6.5V +3.5V −3V
A30 Modulation Filter J31
✔✔
A29 20 GHz Doubler J32
✔✔
A27 40 GHz Doubler J33
✔
A36 Quadraplier J34
✔✔✔