Before replacing a Field Replaceable Unit (FRU), what should a technician always do?

Before replacing a Field Replaceable Unit (FRU), it is essential for a technician to review the FRU process in the Hardware Maintenance Manual (HMM) because this manual contains critical information about the proper procedures, specifications, and guidance for handling FRUs. It ensures that the technician is aware of the steps required for safely and effectively replacing the part while minimizing the risk of further damage to the device.

By consulting the HMM, the technician can verify the correct part number, understand how to correctly disassemble and reassemble the device, and follow any specific safety precautions or handling guidelines. This comprehensive understanding ultimately contributes to a more efficient repair process and enhances the overall quality of service provided to the customer.

The other options, while they may hold some significance, do not prioritize the fundamental knowledge necessary for the FRU replacement process in the same way that reviewing the HMM does. For instance, customer approval is essential in certain contexts but is secondary to understanding the technical requirements of the replacement. Checking inventory is practical, but without understanding the correct procedures, having the part on hand doesn't ensure the repair will be done correctly. Diagnostic tests can be important in determining the need for an FRU replacement but should follow the review of the HMM to confirm the