Keysight E8257D/67D - Self-Tests 10 Xx: A7 Reference (Option UNR;UNX and Instruments with Serial Prefixes >= US4805;MY4805) Self-Test Errors

E8257D/67D, E8663D PSG Signal Generators Service Guide
Troubleshooting
Troubleshooting Assembly–Level Problems
1-44
Self–Tests 10xx: A7 Reference (Option UNR/UNX and Instruments with Serial Prefixes >= US4805/MY4805)
Self–Test Errors
Before proceeding to the reported self–test error code, check the following voltages. If any voltages are out of
specification troubleshoot the supply problem first.
1000 Power Supply
• Replace the A7 Reference.
1001 10 MHz Test
1. Using an oscilloscope, check P41–2 for a 10 MHz signal greater than 1.12 V
p–p
. If the signal is present, replace the
A7 Reference.
2. If the signal is not present, the problem could be the 10 MHz Reference or the signal path from the 10 MHz
Reference.
3. Check the 10 MHz reference oscillator output signal.
a. If the 10 MHz signal is not present on the output port, measure the 10 MHz power supply voltages on the rear
panel interface board. The following voltages should be observed:
•Pin 1 ground
• Pin 2 +12V
•Pin 3 ground
• Pin 4 a positive DC voltage around +3.8V should be present (oven cold raw voltage may vary).
Supply Voltage
(Vdc)
Connector Pins Minimum Value
(Vdc)
Maximum Value
(Vdc)
Origin
+15 P42–6, 21 +14.55 +15.45 Main Supply
–15 P42–2, 17 –14.55 –15.45 Main Supply
+9 P42–5, 20 +8.82 +9.18 YIG Driver