Section II. TROUBLESHOOTING
The disk unit is a complex piece of electronic equipment. Organizational maintenance personnel perform only those
troubleshooting procedures contained within this manual. If a malfunction occurs that is not covered in this manual, or if
the listed maintenance action does not correct the trouble, the disk unit is removed from its mounting and replaced with a
functioning spare disk unit. The defective disk unit is then referred to higher levels of maintenance for repair.
This manual cannot list all malfunctions that might occur, or all tests, inspections, and
corrective actions required. If a malfunction is not listed, or is not resolved by the listed
corrective actions, notify the shift supervisor.
Locate the malfunction in the Symptom Index.
Note that the troubleshooting flowcharts and procedures are indexed by malfunction/symptom.
Review the sample flowchart (fig. 4-1) to become familiar with the proper use of troubleshooting flowcharts.
Table 4-1 provides
of probable equipment malfunction symptoms. Use the index
to quickly locate applicable
troubleshooting flowchart and/or procedures to determine the required corrective action(s).
DO NOT remove the HDA or cabling with the unit's power on. Position PWR ON/PWR
OFF switch to PWR OFF first.
Always handle the disk unit with extreme care, especially the HDA. Improper handling
of the unit can cause head crashes.