SMI300XS Supermicro MI300X GPU Service Specialist (SMI300XS) Exam Question and Answers

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.

When servicing theSupermicro MI300X GPU system, there are3 screwssecuring thebracket at the bottom of the motherboard trayin front of the backplane.

Purpose of these screws:

They secure the backplane’s structural integrityto prevent vibration-related failures.

Loosening them allows the removal or replacement of backplane componentssafely.

They prevent accidental disconnectionscaused by handling or system movement.

Why other options are incorrect?

A (13 screws)→ This number istoo highfor just the bottom bracket.

B (21 screws) & C (30 screws)→ These numbersapply to entire system disassembly, not just the bottom bracket.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Disassembly Guidespecifies thatonly 3 screwsneed to be loosened to access thebottom bracket securing the backplane.

Themidplane lid removal processis designed to betool-freeand follows aspecific sequence to avoid damage.

Thecorrect methodis:

Push in on the two handleslocated near thePCIe tray.

Slowly lift the midplane lid up, ensuring it does not catch on other components.

Remove the lid at an angleto avoid damaging adjacent connectors.

Why this method is used?

Theangled removalhelpsavoid contact with fragile connectorson the midplane.

Forcing the lid straight upcould damage PCIe slots or motherboard connectors.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Disassembly Manualdetails thecorrect method for removing the midplane lid.

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.

Why Must All Cables Be Moved Out of the Way?

Themidplane bracket in Supermicro MI300X GPU systemshousesmultiple power and data connections. If cables are not movedout of the way before lowering the bracket, the following issues can occur:

Cable Pinching or Crushing

If cables are trapped beneath the midplane,their insulation can get damaged, leading to potentialshort circuits or power failures.

Improper Connector Alignment

Misplaced cablesmay obstruct connector seating, preventingMCIO, PCIe, or NVMe connections from fully engaging.

Potential Performance Issues

If data cables are twisted or bent sharply,signal integrity issuesmay arise, causingintermittent connectivity failures.

Step-by-Step Safe Midplane Installation:

✅Step 1:Identify all power and data cables before lowering the midplane bracket.✅Step 2:Move all cables out of the way and neatly route them along their designated pathways.✅Step 3:Slowly lower the midplane bracket into position, ensuring cables remain free from obstruction.✅Step 4:Check that all connectors are accessible and that no cables are trapped under the bracket.

Why Other Options Are Incorrect?

A (Only move the ribbon cable)→ Other cables may still be in the way, risking damage.

B (Only move the power cable)→ Power cables are important, butdata cables must also be repositioned.

C (Only move the I2C cable)→ The I2C cable alone is not enough;all cables need clearance.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Service Manualspecifies thatall cables must be moved before lowering the midplane bracket to avoid obstruction and damage.

Why Must the Screws Be Loosened First?

ThePCIe, motherboard, and GPU trays in Supermicro MI300X systemsaresecured by screws on both sidesto ensure:

Structural stability

Vibration resistance

Secure connection of PCIe lanes and data paths

Proper Tray Removal Process:

✅Step 1:Identify the tray to be removed (PCIe, motherboard, or GPU).✅Step 2:Loosen screws on both sidesto release tension on the tray.✅Step 3:Slowly and evenlypull the tray outto avoid damaging connectors.✅Step 4:Support the tray from the bottomwhile sliding it out to prevent bending.

Why This Method Is Important?

Preventing Connector Damage→ Pulling the tray without loosening screwscould damage PCIe connectorsor misalign the board.

Avoiding Strain on Other Components→ A stuck traycould put pressure on adjacent cables and connectors.

Ensuring a Safe Removal→ The slow and controlled movementreduces the risk of accidentally dropping or flexing the tray.

Why False Is Incorrect?

IfFalse were correct, it would suggest that the tray can be removedwithout loosening screws, which isnot possibledue to the secure mounting system.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Hardware Maintenance Guideconfirms thatloosening screws and carefully pulling the tray out is the correct disengagement procedure.

Importance of Mapping Cables Before Disconnection

TheNVMe backplaneinSupermicro MI300X systemsuseshigh-speed PCIe lanesandpower distribution linesthat must beproperly mapped before disconnection.

Why Should Cables Be Mapped?

Prevents misconnection during reassembly

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

Misplacing a cable in the wrong portcan causeboot failures, drive detection issues, and system instability.

Reduces downtime for troubleshooting

Without a mapped diagram or a picture, technicians may spendhours debugging misconnected cables, leading todelays in system restoration.

Ensures proper airflow and cable management

Incorrectly routed cablescanblock airflow, leading tooverheating and thermal throttling of GPUs or storage devices.

Correct Process for Cable Mapping

Take high-resolution picturesbefore disconnecting cables.

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

Create a simple mapping diagramshowing 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 Guidestates thatproper cable mapping is required before NVMe backplane disconnectionto avoid misplacement.

Removing the motherboardrequires careful handlingto preventbending pins, PCB damage, or static discharge.

Correct Removal Process:

First, remove all 12 screws securing the motherboard.

Avoid touching any exposed pins or contacts.

Carefully slide the motherboard slightly out of the rear of the tray.

Support it with one hand underneath to prevent bending.

Continue sliding it out without tilting it.

Why other options are incorrect?

A (Touch pins & shove motherboard)→ Touching pins cancause electrostatic damageandforcing it out can damage components.

B (Hold like a pizza)→ Usingone handdoes not provide enough support, increasing the risk ofbending or dropping the motherboard.

C (Tilt chassis & shake it out)→ This is acompletely impropermethod and canseriously damageconnectors and PCB components.

Official Documentation Reference:

Supermicro MI300X System Removal Guideadvises toslide the motherboard out carefully while supporting it underneath.

When working withSupermicro MI300X GPU systems, it ishighly recommendedtomap or take a pictureof cable connections before disconnection.

Reasons:

Ensuring Proper Reconnection→ NVMe backplanes have multiplecritical connections(MCIO cables, power cables, data lanes, and SAS connections). Misplacing any of these cables could cause:

Boot failures

Drive detection issues

Performance degradation

Avoiding Errors in Cable Routing→ Supermicro documentation states thatimproperly routed cables can obstruct airflow, potentially leading tooverheatingin high-performance systems.

Easing Future Troubleshooting→ If issues arise after reassembly, aphoto or cable mapallows engineers toquickly verifywhether cables werereconnected properly.

This best practice isofficially recommendedinSupermicro’s service and installation guidelinesfor NVMe backplanes.