71If an alarm rings out, the administrator must read the error message on the terminal or thePAC Management Software screen to determine what has triggered the alarm, and thentake appropriate actions to rectify the problem. The alarm can be turned off using themute button on the front panel and the Alarm beep pattern is described in theTroubleshooting Guide included in the CD-ROM.NOTEWhen temperature exceeds a preset threshold, the controller’s charger circuits willstop charging. You will then receive a message that reads “Thermal Shutdown/EnterSleep Mode.” When the temperature falls back within normal range, thesupercapacitor will resume charging.I2CThe operating status of PSU and cooling fan modules are collected through an I2C serialbus. If either of those modules fails, the failure will be detected and you will be notifiedthrough the same methods as in the audible alarms.System MaintenanceWARNINGDo not remove a failed component from the system until you have a replacement onhand. If you remove a failed component without immediate replacement, it will disruptthe internal airflow.Qualified engineers who are familiar with the system should be the only ones whomake component replacements.When inserting a removable module, do not use excessive force. Forcing orslamming a module can damage the connector pins either on the module itself or onthe backplane.The following components can be replaced: Controller module (please refer to Replacing the Controller Module) Memory module (please refer to Replacing Memory Module(s)) CBM module (please refer to Replacing the Cache Backup Module (CBM)) Host board (please refer to Replacing the Controller Host Board) PSU module (please refer to Replacing the Power Supply Module) Hard drive (please refer to Replacing the Hard Disk Drive)Restoring Default System SettingsNOTERestoring default settings is a last-resort function. All configurations, such asparameters and host LUN mappings, will be erased.
