LaCie 12big Rack Network Troubleshooting & Problem SolvingUser Manual page 344.6. Drive Carrier Module FaultsEach Drive Carrier module incorporates two LEDs, Upper (Green)and Lower (Amber), shown in Fig. 10.✦ In normal operation the Green LED will be ON and will flickeras the drive operates✦ In normal operation the Amber LED state will be:– – OFF if there is no drive present,– – OFF as the drive operates, and– – ON if there is a drive fault present.IMPORTANT INFO: Dummy Drive Carrier modules must be fittedto all unused drive bays to maintain a balanced air flow.4.7. Dealing with Hardware FaultsEnsure that you have obtained a replacement module of the sametype before removing any faulty module.CAUTION: If the LaCie 12big Rack Network subsystem is poweredup and you remove any module, replace it immediately. If the sub-system is used with modules or module blanks missing for more thana few minutes, the enclosure can overheat, causing power failureand data loss. Such use will invalidate the warranty.✦ Replace a faulty drive with a drive of the same type and equalor greater capacity.✦ All drive bays must be fitted with a Drive Carrier module inorder to maintain a balanced air flow.✦ All the supplied plug-in power supply units, electronics mod-ules and blank modules must be in place for the air to flowcorrectly around the cabinet.CAUTION: Observe all conventional ESD precautions when han-dling LaCie 12big Rack Network modules and components. Avoidcontact with Backplane components and module connectors, etc.IMPORTANT INFO: The top cover of the enclosure covers a ser-vice area which should be accessed by service personnel only. Whenthe cover is replaced it MUST be secured by turning the lock mecha-nism to the “locked” position.4.8. Continuous Operation DuringReplacementDepending on how the enclosure system is set up, if a disk unitfails, it can normally be replaced without interrupting the use of thesystem.If an enclosure contains two Power Supply Units, either of them canmaintain power to the subsystem while the other is replaced.