Understanding the AOM Bracket in Supermicro MI300X Systems

The AOM (Add-On Module) bracket is used to hold optional expansion cards , such as:

RAID controllers

Additional network interface cards (NICs)

BMC/IPMI modules for system management

Why is the Screw Located on the Side of the Motherboard Tray?

The AOM bracket is secured to the chassis via a single screw that is located on the side of the motherboard tray .

This design keeps the bracket firmly in place while still allowing for easy removal when needed .

Removing the screw first prevents unnecessary strain on the bracket and ensures safe removal of the AOM card .

Why Other Options Are Incorrect?

A (On top of the hard drive tray) → The hard drive tray does not secure the AOM bracket.

B (On top of the fan tray) → Fans do not hold down the AOM bracket.

D (On the rear of the power supply) → The power supply is not directly connected to the AOM bracket .

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Expansion Module Guide specifies that the AOM bracket is secured by a single screw located on the side of the motherboard tray .

The correct and safe method to remove the backplane from the motherboard tray is to use both hands , gently tilting the top of the backplane towards yourself while carefully lifting it up and out of the motherboard tray.

This ensures that:

No undue force is applied to the connectors or PCB.

No components or cables are unintentionally damaged.

Proper handling of static-sensitive components is maintained.

Removing the backplane improperly can result in:

Connector damage to the motherboard or backplane.

PCB warping , which could lead to future malfunctions.

Potential data center downtime due to component failure.

According to Supermicro's official documentation , this method aligns with industry best practices and recommended service procedures for Supermicro MI300X GPU systems .

Removing the midplane in a Supermicro MI300X GPU system requires disengaging multiple system trays and power components beforehand.

Why is this necessary?

Power must be fully disengaged before midplane removal

The midplane is directly connected to power distribution units (PDUs) .

If power is not removed, it can cause short circuits or hardware damage .

PCIe, motherboard, and GPU trays block access

These trays must be disengaged before removing the midplane , as they contain components directly connected to it.

Dummy PSUs must also be removed

Even inactive PSUs contain locking mechanisms that must be disengaged.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 System Removal Guide confirms that PSUs, dummy PSUs, PCIe trays, motherboard trays, and GPU trays must be removed before handling the midplane .

Importance of Proper Alignment in Motherboard Tray Installation

The motherboard tray in Supermicro MI300X systems is precisely designed to fit into pre-existing grooves in the chassis .

Ensures a Secure Fit

If the motherboard tray is not aligned with the grooves , it may not seat correctly , causing structural instability.

Prevents Cable Routing Issues

Improper alignment can interfere with airflow and cable routing , leading to cooling inefficiencies.

Guarantees Proper PCIe and Power Connections

Misalignment can cause PCIe slots and power connectors to be slightly off-position , leading to failed component detection .

Proper Installation Steps for the Motherboard Tray:

✅ Step 1: Slide the motherboard tray into the chassis grooves for proper alignment. ✅ Step 2: Ensure it is flush with the chassis before securing screws. ✅ Step 3: Tighten screws evenly to prevent misalignment.

Why is False Incorrect?

If False were correct , it would imply that the motherboard tray can be installed without aligning it properly , which is not possible in Supermicro MI300X systems.

The system will not function properly if the motherboard tray is misaligned.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Service Manual confirms that the motherboard tray must be aligned with the grooves before securing it with screws .

When reinstalling trays (GPU, motherboard, or PCIe) in Supermicro MI300X GPU systems , it is crucial to secure one end first before working on the opposite end.

Why is this necessary?

To prevent tray misalignment

Trays in Supermicro systems have specific guide rails and screws that must be aligned correctly before full installation .

If both ends are handled simultaneously, one end may shift , causing mounting misalignment .

Avoiding unwanted movement

If you install a tray at both ends without securing one first, it can get pushed out , leading to incorrect seating.

This can cause poor PCIe connectivity, power delivery issues, or misaligned airflow paths .

Ensuring cables are properly routed

If a tray is not secured properly, cables may shift during installation , increasing the risk of pinched or damaged cables.

Why other options are incorrect?

B (Cables getting in the way) → While cable management is important, the key issue is tray movement , not cables.

C (Tray will not function) → The tray will function once properly seated , but incorrect installation can cause connectivity issues .

D (Tray will break) → The tray is designed for durability; it will not break unless excessive force is applied .

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Service Guide confirms that trays must be secured at one end before installing the opposite end to ensure proper alignment .

To remove the midplane bracket in the AS-8125GS-TNMR2 system , you must remove 4 screws total ( 2 on each side of the chassis ).

Why 4 screws?

The midplane bracket is secured by 2 screws per side to maintain its structural integrity.

Loosening all 4 screws allows safe removal without excessive force .

Forcing the bracket without removing the screws risks damaging the mounting points .

Incorrect Answers Explained:

A (2 screws total) → Not enough, as screws on both sides must be removed.

C (8 screws total) → More than necessary; only 4 screws hold the midplane bracket .

D (6 screws total) → Incorrect count; only 2 screws per side are required .

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Installation Guide explicitly states that two screws on each side (4 total) must be removed to release the midplane bracket .

The correct order for removing trays before midplane removal is:

Disengage the PCIe tray first

This tray must be removed first because it provides access to the underlying system components .

Remove the GPU tray

The GPU tray sits between the PCIe and motherboard trays and must be disengaged after PCIe components are cleared.

Remove the motherboard tray last

The motherboard tray is the final component before midplane removal .

Removing it last ensures full access to the system components without obstructing critical connections .

Why other options are incorrect?

B (Motherboard before GPU tray) → The motherboard tray must be removed last to avoid disconnecting system-critical connections too early.

C (Motherboard tray first) → Removing the motherboard first risks damaging PCIe and GPU components.

D (GPU tray first) → The GPU tray is dependent on the PCIe tray being removed first , making this order incorrect.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 System Removal Guide outlines the correct order for tray disengagement before midplane removal .

The AOM (Add-On Module) bracket is used to mount optional components like:

RAID controllers

Additional networking interfaces

BMC/IPMI modules

In the example system shown in the video , the right AOM bracket does not contain an AOM card . This is because:

Supermicro’s default system configurations do not always ship with optional AOM cards.

The left AOM bracket usually houses optional RAID or networking expansions , but the right bracket remains unoccupied unless a specific expansion module is installed.

Official Documentation Reference:

Supermicro Hardware Deployment Guide confirms that the right AOM bracket is optional and not pre-installed in base configurations.

Importance of Mapping Cables Before Disconnection

The NVMe backplane in Supermicro MI300X systems uses high-speed PCIe lanes and power distribution lines that must be properly mapped before disconnection .

Why Should Cables Be Mapped?

Prevents misconnection during reassembly

The system uses multiple identical-looking cables (MCIO, NVMe, and power cables).

Misplacing a cable in the wrong port can cause boot failures, drive detection issues, and system instability .

Reduces downtime for troubleshooting

Without a mapped diagram or a picture, technicians may spend hours debugging misconnected cables , leading to delays in system restoration .

Ensures proper airflow and cable management

Incorrectly routed cables can block airflow , leading to overheating and thermal throttling of GPUs or storage devices .

Correct Process for Cable Mapping

Take high-resolution pictures before disconnecting cables.

Label each cable and its corresponding port using numbered stickers or colored tags.

Create a simple mapping diagram showing which cable connects to which port.

Double-check the mapping before removal.

Why Other Options Are Incorrect?

B (Disconnect the power supply first) → While powering down is important, mapping cables is the primary precaution before disconnection .

C (Randomly disconnect cables) → Leads to confusion and potential system failures due to incorrect reconnections.

D (Shake the system to loosen cables) → NEVER shake a server , as this can damage internal components and misalign connectors.

Official Documentation Reference:

Supermicro NVMe Installation Guide states that proper cable mapping is required before NVMe backplane disconnection to avoid misplacement.

For Supermicro MI300X GPU systems , removing the power supply unit (PSU) improperly can lead to serious issues.

Why the red lock exists?

The red locking mechanism ensures that the PSU is properly secured in the system.

Before disengaging the PSU, the red lock must first be unlocked to avoid damage.

If you forcefully shift the release lever without unlocking the red lock:

B: The power supply unit will fail → If the PSU is removed improperly, it can cause internal damage to power connectors, resulting in PSU failure or improper functioning .

C: You could permanently damage the lock on the power supply unit → The locking mechanism is designed for smooth disengagement. Forcefully shifting the lever can break or warp the lock, making it impossible to secure the PSU back in place .

Incorrect Answers Explained:

A (All answers are correct) → This is incorrect because not all answers are valid .

D (The PSU can no longer be secured into the tray) → This happens only if the lock is damaged , which is covered under option C .

Supermicro’s official documentation clearly states that unlocking the red lock first is a critical step before removing or replacing the PSU.