Fluke 5500A, Service Manual

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Maintenance
Diagnostic Testing
4
4-7
4-9. Diagnostic Testing
5500A internal software provides extensive self-testing capabilities. In case of a
malfunction, this is an excellent place to begin testing to isolate a faulty module.
Note
Self-tests should only be run after the 5500A has completed its warm-up.
Access the diagnostics menu as follows:
Press
S
followed by UTILITY FUNCTNS, and SELF TEST. The menu presents the
following choices:
•
PSEUDO CAL -- Runs all the internal gains calibration steps, but does not save the
updated constants. This is useful to check for error messages.
•
DIAG -- Runs internal diagnostics.
•
FRONT PANEL -- Allows you to test the front panel knob, keys, bell, and displays.
•
SERIAL IF TEST -- Does a loopback test between the two serial ports. For this test,
you attach a straight-through serial cable between the two serial ports. At least pins
2, 3, and 5 need to be connected.
•
DIGITAL TEST -- Checks the RAM and bus on the Main CPU (A9).
4-10. Running Diagnostics
Press
S
followed by UTILITY FUNCTNS, SELF TEST, and DIAG. The menu
presents the following choices: OPTIONS and GO ON. Press GO ON to start
diagnostics. The 5500A prompts you to remove all cables from the front panel outputs.
4-11. Sequence of Diagnostics Tests
After you press the GO NO softkey, an automatic sequence of tests begins. Diagnostics
runs the following tests:
•
General and DDS assembly (A6) diagnostics (23 steps)
•
Current assembly (A7) diagnostics (24 steps)
•
Synthesized Impedance assembly (A5) diagnostics (26 steps)
•
Voltage assembly (A8) diagnostics (16 steps)
4-12. Diagnostics Error Messages
If an error message appears during diagnostics, check the following annotated list to
determine which assembly, and what circuit, is suspect. You should perform the
diagnositics in proper sequence. Each diagnostic test builds on the successful pass of the
previous diagnostic test in order to properly diagnose a faulty subcircuit. The assembly
named in the error message is almost always the assembly that has the fault.
1006 (DDE:FR ) A6 DCI loop fault
Suspects include U57, U31, and U33 on the A6 assembly.
1007 (DDE:FR ) A6 ACI loop fault
Suspects include U3, U14, U34, U37, U38, U44, U47, U84, and U90 on the A6
assembly.