Supermicro Supermicro MI300X GPU Service Specialist (SMI300XS) Exam SMI300XS Exam Dumps: Updated Questions & Answers (October 2025)

Themidplane bracketinSupermicro MI300X GPU systemsconnects multiple crucial components, includingstorage, PCIe devices, and power distribution systems.

Why must the MCIO and Flat Panel/Ribbon cables be removed?

MCIO Cable (Option B)→

MCIO (Multi-lane Cable I/O)cables are responsible forhigh-speed NVMe communicationbetween the motherboard and storage components.

These cables must bedisconnected before midplane removal, asforcing them out without removal can cause connector damage.

Flat Panel/Ribbon Cable (Option C)→

Theflat panel/ribbon cableis used forsystem communication, front panel connectivity, or sensor data transmission.

If not removed, it can be torn or pinched, leading tomalfunctioning front panel indicators, buttons, or management controllers.

Incorrect Answers Explained:

A (Power cable)→ Power cables are usuallysecured independentlyand arenot directly attached to the midplane bracket. Removing them isnot a required stepfor midplane bracket removal.

D (SATA cable)→ SATA cables arefor legacy storage systemsanddo not need to be disconnectedunless working on SATA-specific backplanes.

Official Documentation Reference:

SupermicroService ManualforAS-8125GS-TNMR2explicitly states thatMCIO cables and ribbon cables must be removed before handling the midplane bracketto preventsystem damage.

Thecorrect order for removing trays before midplane removalis:

Disengage the PCIe tray first

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

Remove the GPU tray

TheGPU tray sits between the PCIe and motherboard traysand must be disengaged after PCIe components are cleared.

Remove the motherboard tray last

The motherboard tray isthe final component before midplane removal.

Removing it lastensures full accessto the system componentswithout obstructing critical connections.

Why other options are incorrect?

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

C (Motherboard tray first)→ Removing the motherboard firstrisks damagingPCIe and GPU components.

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

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 System Removal Guideoutlines the correct order fortray disengagement before midplane removal.

Understanding MCIO Cables in Supermicro MI300X Systems

MCIO (Multi-lane Cable I/O) connectorsare used forhigh-speed data transmission between the motherboard and NVMe SSDs or PCIe devices.

These connectorsmust be handled carefully, as improper removal cancause pin damageorpermanent failure of the interface.

How to Properly Unlock and Release MCIO Cables

Locate the release levers on the MCIO connectors

Each MCIO connector has asmall built-in release leverthat locks it in place.

Press down on the release levers

This disengages the locking mechanism andallows the cable to slide out easily.

Gently pull the MCIO cable straight out

Do not pull at an angleas it can damage thehigh-density connector pins.

Why Other Options Are Incorrect?

A (Pull really hard)→ Forcing the connector without releasing the latch canbreak the MCIO pins or damage the motherboard socket.

B (Remove screws)→ MCIO cablesdo not use screws; they have built-in locking mechanisms.

D (Loosen bolts)→ There areno boltssecuring MCIO cables; only therelease lever is needed for unlocking.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Motherboard Manualstates thatpressing down on the release levers is the correct method to unlock MCIO cables.

Components Located on Top of the Motherboard in Supermicro MI300X Systems

Fans and Fan Shrouds (Option A)

These are installedabove the motherboardtodirect airflow over the components.

Fan shrouds help focus airflow, ensuringefficient cooling of CPUs and GPUs.

Support Bar and AOM Brackets (Option B)

Thesupport bar reinforces the motherboard tray, preventing flexing.

AOM bracketshold optionalnetworking or RAID expansion modules.

Heatsinks and CPUs (Option C)

Large heatsinks are mounted on top of the CPUsto dissipate heat.

These ensureoptimal thermal managementof high-performanceAMD MI300X GPUs and processors.

Why Option D (DIMM Modules) is Incorrect?

❌DIMM modules (memory sticks) are installed in slots beside the CPU, but they arenot physically above the motherboardin a way that they could be considered a top-mounted component.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 System Overviewconfirms thatfans, heatsinks, AOM brackets, and support bars are mounted on top of the motherboard.

Themidplane in Supermicro MI300X GPU systemsis responsible for interconnecting several system components. The twoprimary cablesthat must be removed before handling themidplaneare:

I2C Cable (Inter-Integrated Circuit Cable)

This cable is used forsensor data, system monitoring, and thermal control.

If not disconnected, it couldsnap or cause sensor miscommunicationbetween the motherboard and the backplane.

Power Cable

This cablesupplies powerto the midplane andmust be disconnected before removalto avoid electrical damage.

Removing the midplanewhile power cables are still attachedcould short-circuit the system.

Why is this step necessary?

Supermicro's official documentation states that both the I2C and power cables must be disconnected before handling the midplane.

Failure to remove these cables properly can cause permanent damage to connectors and the system board.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Maintenance Manualconfirms thatdisconnecting the I2C and power cables is mandatory before midplane removal.

Theyellow warning labelis a critical indicator toprevent damagewhen servicing themidplane and ribbon cable connections.

Reason for Warning Label:

Theflat panel/ribbon cable is delicateand isconnected between multiple system components.

If themidplane is removed first, itstretches and applies force on the ribbon cable, leading to:

Broken cable connectors

Torn ribbon cable

System interface failure(front panel controls, LED indicators, or data communication)

Why other options are incorrect?

A (Cable is hot)→ Ribbon cablesdo not generate heatand thisis not the purpose of the warning label.

B (Remove after midplane)→ Thecable must be removed BEFORE the midplane, not after.

C (Optional removal)→It is mandatory, not optional, to prevent damage.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Maintenance Manualstates thatremoving the flat panel/ribbon cable firstisa required stepbefore handling the midplane.

Thecorrect and safemethod to remove the backplane from the motherboard tray is to useboth hands, gently tilting thetop of the backplanetowards yourself while carefullylifting it up and outof the motherboard tray.

This ensures that:

No undue forceis applied to the connectors or PCB.

No components or cablesare unintentionally damaged.

Proper handling of static-sensitive componentsis maintained.

Removing the backplane improperly can result in:

Connector damageto the motherboard or backplane.

PCB warping, which could lead to future malfunctions.

Potential data center downtimedue to component failure.

According toSupermicro's official documentation, this method aligns withindustry best practicesandrecommended service proceduresforSupermicro MI300X GPU systems.

Understanding the Midplane in Supermicro MI300X Systems

Themidplane in the Supermicro MI300X GPU systemacts as acentral connection hubthat links various system components, such as:

NVMe storage backplanes

PCIe interconnects

Power distribution pathways

Motherboard to GPU communication lanes

Because of itsdelicate nature and multiple connectors,it must be removed carefullyto avoiddamaging fragile electrical contacts.

Correct Midplane Removal Process

Tosafely remove the midplane, follow theseSupermicro-recommendedsteps:

Ensure all power is fully disconnected

Shut down the systemproperly.

Remove all power cablesanddisconnect all PSUs.

Ground yourself using an anti-static wrist strapto preventelectrostatic discharge (ESD)damage to sensitive components.

Detach all necessary trays and cables

Disengage the PCIe tray, motherboard tray, and GPU trayto ensure clear access.

Disconnect all MCIO cables, power cables, and ribbon cablesto prevent accidental pulling or tearing.

Use both hands for removal

Place both hands firmly on the midplane bracket.

Lift the midplane bracket straight upto ensure a smooth removal process.

Avoid angling or twisting the midplaneas this candamage its connector pins.

Ensure no resistance is felt

If the midplanedoes not lift easily,double-check for any remaining screws or connected cablesbefore applying force.

Why Using Both Hands is Crucial?

Prevents bending or flexing

The midplane is alarge PCB with multiple connection points.Using both hands ensures even lifting pressure, preventing PCB bending.

Avoids strain on connectors

If removed at an angle, it canstress delicate connectors, leading to permanent damage.

Ensures a firm grip

Some components inside the systemcan be heavy. Using both handsensures stability and reduces risk of dropping.

Why Other Answers Are Incorrect?

If False were correct, it would suggest improper handling techniques that can damage the system.

Supermicro documentation clearly states that the midplane must be removed using both hands and in an upright motion.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Disassembly Guideinstructs technicians to useboth hands and lift straight upto prevent damage.

ForSupermicro MI300X GPU systems,removing the power supply unit (PSU) improperlycan lead to serious issues.

Why the red lock exists?

Thered locking mechanismensures that thePSU is properly securedin the system.

Before disengaging the PSU, thered lock must first be unlockedto 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 causeinternal damageto power connectors, resulting in PSUfailure or improper functioning.

C: You could permanently damage the lock on the power supply unit→ Thelocking mechanismis designed for smooth disengagement. Forcefully shifting the lever canbreak or warpthe lock, making itimpossible to secure the PSU back in place.

Incorrect Answers Explained:

A (All answers are correct)→ This is incorrect becausenot all answers are valid.

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

Supermicro’s official documentation clearly statesthatunlocking the red lock firstis a critical step before removing or replacing the PSU.

Why Must the Support Bar Be Removed First?

Thesupport baris areinforcement structureinside the chassis that providesmechanical stabilityto components, including theAOM bracket.

Since the AOM bracket is partially covered by the support bar, you mustremove the bar firstto gain full access.

Step-by-Step Removal Process:

✅Step 1:Remove the screws securing the support bar.✅Step 2:Carefully lift and remove the support bar without tilting it.✅Step 3:Now, unscrew and remove the AOM bracket.

Why is False Incorrect?

IfFalse were correct, it would suggest that the AOM bracket can be removedwithout touching the support bar, which isnot possibledue to obstruction.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Disassembly Manualconfirms that thesupport bar must be removed first before accessing the AOM bracket.