Agilent Technologies E8362C Service Manual page 91

PNA Series Microwave Network Analyzers
E8362C, E8363C, E8364C
If the Fans Are Not Operating
CAUTION The power supply may be in thermal shutdown if the instrument has been operating without
the fans running. Allow the instrument to cool down before troubleshooting.
If all three fans are not operating, suspect a power supply problem or a defective A14 system motherboard.
Refer to "Power Supply Check" on page 4-7
specifications, the most probable cause is a defective A14 system motherboard. Refer to
Replacing the A14 System Motherboard" on page
If only one or two fans are not functioning, and the power supplies are within specifications, suspect the
A14 system motherboard or a defective fan. Perform the following procedure.
1. Remove the front panel assembly from the instrument. Refer to
Panel Assembly" on page
2. Refer to Figure 4-3. Measure the fan voltages at J1, J3, and J4 on the A14 system motherboard.
Figure 4-3 Fan Voltages
3. If the correct voltage is present and the fan connector is in good mechanical condition, suspect a
defective fan. Refer to
4. If the voltage is not present, suspect a defective A14 system motherboard. Refer to
Replacing the A14 System Motherboard" on page
Service Guide E8364-90038
to check the individual supplies. If the supplies are within
7-26.
7-10.
"Removing and Replacing the Midweb and the B1 Fan" on page
"Removing and Replacing the Front
7-26.
Troubleshooting
Power Up Troubleshooting
"Removing and
7-76.
"Removing and
4-11