IBM 6500-V5P Maintenance Manual - Page 170

Troubleshooting Other Symptoms Display Messages DANGER Hazardous voltages are present in the printer with the power cord connected to the power source. Switch off printer power and unplug the printer power cord before proceeding. Do not connect or disconnect any communication port, teleport, attachment connector, or power cord during an electrical storm. Power off the printer and disconnect the power cord before connecting or disconnecting any communication port, teleport, or attachment cable connector. IMPORTANT Use standard fault isolation techniques to troubleshoot malfunctions that are not indicated 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 conditions reported by the user. 3. Look for a match in the General Symptom List that begins on page 176. If you find a match, go to the troubleshooting procedure and follow the numbered instructions. 4. If you do not find the symptom in the General Symptom List, use the Half-Split Method to find the malfunction: a. Start at a general level and work down to details. b. Isolate faults to half the remaining system at a time, until the final half is a field-replaceable part or assembly. Do not attempt field repairs of electronic components or assemblies. Replace a malfunctioning electronic assembly with an operational spare. Most electronic problems are corrected by replacing the printed circuit board assembly, sensor, or cable that causes the fault indication. The same is true of failures traced to the hammer bank: replace the entire shuttle frame assembly. It is not field repairable. 5. Replace the defective part or assembly. 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 the reported symptoms disappear. 170