In Supermicro systems like the SYS-421GE-TNHR2-LCC, the air shroud on the motherboard tray is typically a lift-off component not obstructed by a support bar. Unlike some designs with structural bars, Supermicro’s high-end servers (per manuals like SYS-420GP-TNAR) often feature open tray layouts for easy access, especially in DLC configurations where liquid cooling reducesreliance on complex air channels. Options A, B, and C assume a bar exists and must be removed, but no such requirement is standard. The shroud lifts off after screw removal, making D correct. Supermicro’s DLC design simplifies maintenance, supporting this conclusion.References:Supermicro motherboard tray documentation, DLC system accessibility features.

The LPIO (Low-Profile IO) board in Supermicro systems like the SYS-421GE-TNHR2-LCC, part of the PCIe tray, is typically secured by ametal bracketthat must be removed first. This bracket holds the LPIO board and associated cables (e.g., BMC cable) in place, as seen in similar designs (e.g., SYS-420GP-TNAR). Removing it involves unscrewing (often 2 screws) and lifting it off, granting access to the LPIO board. A (GPU tray) is a separate assembly, C (motherboard tray) is unrelated to the PCIe tray’s LPIO, and D (air shroud) covers components but doesn’t secure the board. Supermicro’s DLC systems emphasize modular access, making B the correct step.References:Supermicro PCIe tray service guides, DLC system IO component layouts.

In Supermicro’s high-end servers like the SYS-421GE-TNHR2-LCC, PSUs are typically located at the back of the chassis for accessibility and cooling efficiency, a design consistent with DLC rack-scale solutions (e.g., SYS-420GP-TNAR). The mention of a “dummy PSU tray” suggests a placeholder or empty slot, common in modular designs to maintain airflow or allow future expansion. This layout is standard in Supermicro’s DLC systems, where PSUs power both compute and cooling components (e.g., pumps, CDUs). No contradicting evidence exists, and True (A) aligns with Supermicro’s chassis architecture, making it the correct answer.

References: Supermicro chassis design specs, DLC system PSU placement.

In Supermicro’s high-end systems like the SYS-421GE-TNHR2-LCC, the PCIe tray, often loaded with multiple GPUs (e.g., 8 NVIDIA HGX GPUs in DLC setups), is heavy and complex. Supermicro’s safety guidelines (e.g., SYS-420GP-TNAR Manual) recommend two people for removing such trays due to weight (over 50 lbs with GPUs) and the need to avoid damaging liquid cooling lines or connectors. In DLC systems, the tray integrates with coolant manifolds, adding to its bulk. Thus, True (A) aligns with Supermicro’s expertise in ensuring safe handling of DLC components.References:Supermicro safety instructions, DLC rack-scale system specs.

In Supermicro systems like the SYS-421GE-TNHR2-LCC, M.2 drives are typically mounted on the motherboard for fast storage in high-performance computing (HPC) and AI workloads, often cooled indirectly by DLC systems. To access the M.2 drive, you must:

Remove the motherboard tray from the chassis: This exposes the motherboard where M.2 slots reside.

Remove the air shroud from the motherboard tray: The shroud covers components for airflow or hybrid cooling, and its removal provides access to the M.2 slot.

Option D aligns with Supermicro’s design, as seen in manuals (e.g., SYS-420GP-TNAR), where M.2 drives are motherboard-mounted. A is incorrect since M.2 drives are serviceable; B (GPU tray) and C (fan housing) don’t house M.2 drives in this context. Supermicro’s DLC solutions prioritize motherboard accessibility, making D the correct procedure.

References: Supermicro motherboard tray manuals, DLC system component layouts.

Removing the PCIe tray in the SYS-421GE-TNHR2-LCC requires loosening4 screws, two on each side of the front, per Supermicro’s standard tray removal (e.g., SYS-420GP-TNAR). This ensures secure detachment of the heavy, DLC-integrated tray. B (6 screws) is excessive, C misplaces screws to a GPU tray’s sides, and D (2 screws) under-secures. Supermicro’s DLC systems balance stability and serviceability, making A correct.References:Supermicro PCIe tray removal guides, DLC system tray specs.

Replacing the air shroud onto the motherboard tray in a Supermicro system involves securing it to the tray itself first for stability. The correct screws are those connecting the shroud directly to the motherboard tray, as outlined in Supermicro’s assembly guides (e.g., SYS-420 series). These initial screws align and anchor the shroud, ensuring proper fitment before additional connections (if any). Options B (PCIe tray) and C/D (fan board) are incorrect since the shroud’s primary attachment is to the motherboard tray, not other components. In DLC systems, precise shroud placement enhances cooling efficiency, supporting A as the correct choice.References:Supermicro motherboard tray assembly guides, DLC system component integration.

The side bracket in the SYS-421GE-TNHR2-LCC likely houses networking or management add-ons. TheAOM-PCIe card(e.g., AOM-GP401-PCIE module) andAOC NIC card(networkinterface card) are common components in Supermicro’s DLC systems, enhancing connectivity (e.g., high-speed NICs for AI workloads). A (GPU/PCIe) mixes unrelated categories, C pairs an AOM with a GPU (less likely), and D (AOC/PCIe) lacks specificity. B aligns with Supermicro’s DLC networking focus, making it correct.References:Supermicro add-on card specs, DLC system networking components.

Fans in Supermicro systems, including those with DLC like the SYS-421GE-TNHR2-LCC, are powered by a power cable connecting to the fan board or motherboard. Before removing a fan from its housing, the power cable must be disconnected first to ensure safety and prevent electrical damage, a standard step in Supermicro’s service protocols. PCIe cables (A) connect expansion cards, I2C cables (C) handle communication (not fan power), and SATA cables (D) link storage drives—none are relevant to fan removal. In DLC systems, where fans may supplement liquid cooling, power disconnection remains critical, making B the verified answer.

References: Supermicro fan replacement guides, DLC hybrid cooling safety standards.