After Service Considerations - Keysight Technologies 53147A Service Manual

2 Service

After Service Considerations

Product Safety Checks
The following safety checks must be performed after any troubleshooting and
repair procedures have been completed to ensure the safe operation of the
instrument.
THE RESISTANCE CHECKS DESCRIBED IN THE FOLLOWING TEXT REQUIRE
WARNING
THAT THE POWER CORD BE CONNECTED TO THE INSTRUMENT AND THAT
AC POWER BE DISCONNECTED. BE SURE THAT THE POWER CORD IS NOT
CONNECTED TO AN AC POWER SOURCE BEFORE PERFORMING ANY
SAFETY CHECKS.
1 VISUAL INSPECTION. Visually inspect the interior of the instrument
2 GROUND CONTINUITY TEST. Plug the power cord into the rear- panel power
3 Check any indicated front- or rear-panel ground terminals marked,
4 INSULATION RESISTANCE TEST. Tie the line and neutral pins of the power
Product Performance Checks
After replacement of any functional assembly, perform the operational verification
test in Chapter 1 of this guide,
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for any signs of abnormal internally generated heat, such as discolored printed
circuit boards or components, damaged insulation, or evidence
of arcing. Determine and remedy the cause of any such condition.
receptacle. (DO NOT connect the instrument to AC power at this time.) Using a
suitable ohmmeter, check resistance from the instrument's metallic
connection (such as the rear panel or BNC ground collar) to the ground pin on
the power cord plug. The reading must be less than 1Ω. Flex the power cord
while making this measurement to determine whether intermittent
discontinuities exist.
using the above procedure.
cord plug together. Measure the resistance from the instrument enclosure
(chassis) to the line and neutral pins of the power cord plug.
The minimum acceptable resistance is 2 MΩ. Replace any component which
results in a failure.
Keysight 53147A/148A/149A Assembly Level Service Guide
"Performance Tests - Verifying Specifications"