After Service Product Safety Checks - Agilent Technologies 4338B Service Manual

After Service Product Safety Checks

Warning
Perform the following ve safety checks to verify the safety condition of the 4338B (these
checks may also be used for safety checks after troubleshooting and repair).
1. Visually inspect the interior of the instrument for any signs of abnormal internally generated
heat, such as discolored printed circuit boards and components, damaged insulation, or
evidence of arcing. Determine the cause, and repair.
2. Use an ohmmeter which can accurately measure 0.1 to check the resistance from the
instrument enclosure to the power cord's ground pin. The resistance must be less than
0.1 . Flex the power cord while making this measurement to determine if any intermittent
discontinuities exist.
3. Unplug the 4338B's power plug from the power source. Set the line switch to ON. Tie the
line and neutral pins of the power connector together and check the resistance between
them and enclosure. The minimum acceptable resistance is 5 M . Find and replace any
component which causes the instrument to fail this test.
4. Verify that the correct fuse is installed.
5. Verify that the grounding wire (green and yellow) is secured to the chassis by a screw and
washer.
4-2 T roubleshooting