Printronix P9012, Maintenance Manual

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4–11 Troubleshooting
Symptoms Not Indicated by Fault Messages
Troubleshoot malfunctions not indicated by fault messages using standard
fault–isolation techniques:
1. Debrief the operator for a general description of the problem.
2. Verify the fault by running diagnostic self–tests or replicating conditions
reported by the user.
3. Locate the malfunction using the half–split method:
a. Isolate faults to half the remaining system at a time, until the
final half is a field–replaceable part or assembly. (Chapter 6 lists
all field–replaceable assemblies.)
b. Start at a general level and work down to details.
4. Replace the defective part or assembly.
IMPORTANT
Do not attempt field repairs on electronic components or assemblies —
replace the entire assembly with an operational spare. Most electronic
problems are corrected by replacing the printed circuit board assembly
(PCBA), sensor, or cable that causes the fault indication. The same is
true of electro–mechanical failures traced to the shuttle frame assembly
or the hammer bank. Replace the entire assemblies; they are not field
repairable.
5. Test printer operation after every corrective action.
6. Stop troubleshooting and return the printer to normal operation when the
reported symptom(s) disappear.