Keysight Technologies E8257D Service Manual page 82

Troubleshooting
Troubleshooting Assembly–Level Problems
1208 Quadraplier
1. If the power supplies +15V, −15V, −3V, −5.2V, +6.5V, +3.5V, or −3V fail, refer
2. If the TC902, TC956 or any of the drain currents fail (test indexes 6 through
3. If self–test 20–40 GHz Prelevel, index 25, fails:
4. If self–test 20–40 GHz Prelevel, index 26, fails:
82
to the table on page 78, and check the supplies used by the A35 I/Q
Modulator as they leave A26 MID connector.
If the signals are good at the A26 MID connector, replace the A36
Quadraplier.
24), replace the A36 Quadraplier.
a. On the signal generator, set the following:
Center Frequency: 30 GHz
Power: −20 dBm
RF: On
b. Remove the cable from J6 of the Quadraplier Bias Board and
connect it to a DVM.
c. The signal should measure approximately +5.2 Vdc.
1. If the signal is bad, troubleshoot the RF path.
2. If the signal is good, replace the A36 Quadraplier.
a. On the signal generator, set the following:
Center Frequency: 45GHz
Power: −20 dBm
RF: On
b. Remove the cable from J7 of the Quadraplier Bias Board and
connect it to a DVM.
c. The signal should measure approximately +5.4 Vdc.
1. If the signal is bad, troubleshoot the RF path.
2. If the signal is good, replace the A36 Quadraplier.
E8257D/67D, E8663D PSG Signal Generators Service Guide