List of Messages111Troubleshooting Other SymptomsWARNING Always disconnect the AC power cord from the printer before doing amaintenance procedure. Failure to do so could result in injury to you ordamage to equipment. If you must apply power during maintenance, youwill be instructed to do so in the maintenance procedure.Use standard fault isolation techniques to troubleshoot malfunctions notindicated by display messages. These techniques are summarized below:1. Ask the operator to describe the problem.2. Verify the fault by running a diagnostic printer test or by replicating theconditions reported by the user.3. Look for a match in the General Symptom List, which begins onpage 112. If you find a match, go to the troubleshooting procedure andfollow the numbered instructions.4. If you cannot find the symptom in the General Symptom List, use theHalf-Split Method to find the malfunction:a. Start at a general level and work down to details.b. Isolate faults to half the remaining systems at a time, until the finalhalf is a field-replaceable part or assembly. (Troubleshooting aids arelisted on page 43.)5. Replace the defective part or assembly. Do not attempt field repairs ofelectronic components or assemblies. Most electronic problems arecorrected by replacing the printed circuit board assembly, sensor, orcable that causes the fault indication. The same is true of failures tracedto the hammer bank: replace the entire shuttle assembly because it is notfield repairable.6. Test printer operation after every corrective action.7. Reinstall any parts you replaced earlier that did not solve the problem.8. Stop troubleshooting and return the printer to normal operation when thereported symptoms disappear.
