Figure 7. Compute node components
The parts listed in the following table are identified as one of the following: 
•  Tier 1 customer replaceable unit (CRU): Replacement of Tier 1 CRUs is your responsibility. If Lenovo 
installs a Tier 1 CRU at your request with no service agreement, you will be charged for the installation. 
•  Tier 2 customer replaceable unit: You may install a Tier 2 CRU yourself or request Lenovo to install it, at 
no additional charge, under the type of warranty service that is designated for your server.
•  Field replaceable unit (FRU): FRUs must be installed only by trained service technicians.
•  Consumable and Structural parts: Purchase and replacement of consumable and structural parts 
(components, such as a cover or bezel) is your responsibility. If Lenovo acquires or installs a structural 
component at your request, you will be charged for the service.
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ThinkSystem SN550 Compute Node Maintenance Manual