Service Guide N5242-90001
4-11
PNA Series Microwave Network Analyzers
Troubleshooting
N5242A
Power Up Troubleshooting
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
to check the
individual supplies. If the supplies are within specifications, the most probable cause is a
defective A14 system motherboard. Refer to
“Removing and Replacing the A14 System
If only one or two fans are not functioning, and the power supplies are within
specifications, suspect the A14 system motherboard or defective fan(s). Perform the
following procedure.
1. Remove the fan bracket, with fans attached, from the analyzer to expose the fan power
cable connections on the A14 system motherboard. Refer to
for location of
“Removing and Replacing the Fans” on page 7-60
2. Plug in the power cord and measure the fan voltages at all three connectors on the A14
system motherboard. THIS MUST BE DONE QUICKLY AS THE ANALYZER WILL
RAPIDLY OVERHEAT WITHOUT THE COOLING EFFECT OF THE FANS. DO NOT
PLUG IN THE POWER CORD UNTIL READY TO PERFORM MEASUREMENTS.
Figure 4-3 Fan Power Cable Connections
Содержание N5242A
Страница 11: ...Service Guide N5242 90001 1 1 1 Safety and Regulatory Information...
Страница 19: ...Service Guide N5242 90001 2 1 2 General Product Information...
Страница 33: ...Service Guide N5242 90001 3 1 3 Tests and Adjustments...
Страница 75: ...Service Guide N5242 90001 4 1 4 Troubleshooting...
Страница 119: ...Service Guide N5242 90001 5 1 5 Theory of Operation...
Страница 153: ...Service Guide N5242 90001 6 1 6 Replaceable Parts...
Страница 237: ...Service Guide N5242 90001 7 1 7 Repair and Replacement Procedures...
Страница 303: ...Service Guide N5242 90001 8 1 8 General Purpose Maintenance Procedures...
Страница 342: ...Index 22 Service Guide N5242 90001 Index...