Agilent Technologies 35670A Service Manual page 190

Troubleshooting the Analyzer
To troubleshoot the power supply
Step 6. Determine if the Motherboard, Fan, or Rear Panel assembly is causing the
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Power Supply to shut down.
• Disconnect the fan cable from A99 P90.
• Set the power switch to on (
• If the power supply LED is now on, the A90 Fan assembly is probably
faulty.
• Set the power switch to off (
• Reconnect the fan cable.
• Remove the rear panel and disconnect the cable from A10 P100.
See ''To remove rear panel'' on page 6-7.
• Set the power switch to on (
• If the power supply LED is now on, the A10 Rear Panel assembly is
probably faulty.
• If the Fan or Rear Panel assembly is not causing the Power Supply assembly
to shut down, then the A99 Motherboard is probably faulty.
Step 7. Check the Fan assembly.
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• Set the power switch to off (
• Remove the A7 CPU assembly.
See ''To remove CPU'' on page 6-11.
• Disconnect the fan power cable from A99 P90 (red and black cable).
• Connect 5 Vdc to the fan cable. The fan should be turning slowly.
• Increase the voltage to 10 Vdc. The fan should turn faster as the voltage
increases.
• If the fan did not respond correctly, the A90 Fan assembly is probably
faulty.
• If the fan responded correctly, the A10 Rear Panel assembly is probably
faulty.
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Agilent 35670A