Installation guide

Troubleshooting
Troubleshooting Assembly Level Problems
1-33
200 Power Supply
• If the supply voltages are good on the J10 connector pins indicated:
a. Turn power off to the signal generator.
b. Remove the A15 Sampler (Option UNJ or Option 506) and ohm the connection between the appropriate
J32 and J10 pins.
— If the connection is good, replace the A15 Sampler (Option UNJ or Option 506).
(Refer to “A15 Sampler (Option UNJ or Option 506)” on page 2-36.)
— If the connection is bad, replace the A19 Daughterboard.
(Refer to “A19 Daughterboard” on page 2-44.)
• If the supply voltages are bad on the J10 connector pins indicated:
a. Check the origin of the supply.
— If the supply voltages are good at the origin, replace the A23 Motherboard.
(Refer to “A23 Motherboard” on page 2-52.)
— If the supply voltages are bad at the origin, troubleshoot the problem using that assembly's
troubleshooting procedure.
201 Tuning + Bias Test
CAUTION Do not install the A18 Reference or the A15 Sampler (Option UNJ or Option 506) with the
signal generator powered up or serious damage to the signal generator may be caused.
• With the signal generator powered up, carefully remove the A15 Sampler (Option UNJ or Option 506)
from the signal generator.
• Connect a semi-rigid cable-extender probe to P1 and connect a signal analyzer to the probe.
P1 delivers a 1 GHz signal from J3 of the A18 Reference
to J1 of the A15 Sampler (Option UNJ or Option 506) through W44.
• Check for a 1 GHz signal with a power level ≥ 0dBm.
— If the signal is present and at the correct power,
replace the A15 Sampler (Option UNJ or Option 506).
(Refer to “A15 Sampler (Option UNJ or Option 506)” on page 2-36.)
— If the signal is not present or at the correct power:
a. Turn power off to the signal generator.
b. Remove the A18 Reference.
c. Ohm the center pin of W44; it should measure as a short.
d. Ohm between the center pin and the shield of W44; it should measure as an open.
— If the cable measures good (as defined in the previous two steps), refer to the A18 Reference
troubleshooting procedure.
— If the cable measures bad, replace the cable.