Hardware Failure

Nvidia (Mellanox) SN3420 won't boot at all: Diagnose & Fix

Q: Where can I find the Nvidia (Mellanox) official documentation?

https://docs.nvidia.com/networking/ — search the product family + feature name.

By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30

⚡ At a glance

Vendor	Nvidia (Mellanox)
Operating system	Cumulus Linux / NVOS / SONiC
Category	Hardware Failure
Skill level	Intermediate to advanced
DIY-able?	Yes with CLI access; some scenarios need Nvidia Enterprise Support + RMA.

Across years of operating Nvidia (Mellanox) gear I have watched the same hardware-failure pattern repeat: a unit ships fine, runs for two years, then trips on a power-event or a thermal excursion. On Cumulus Linux / NVOS / SONiC the recovery path is the same whether the affected unit is from the SN3420 family or something newer.

Before you touch anything, capture state. `nv show system` and `nv show platform environment` dumped to a file is worth more than a screen-cap because Nvidia Enterprise Support will ask for the exact output when you open the case. Keep the artifact even if the box recovers on its own.

Below I walk through the on-box steps first, then the Nvidia Enterprise Support escalation path. If you have spares on hand, swap-then-diagnose is usually faster than diagnose-then-swap: but only if you can afford the rack time.

What this guide covers

Diagnose and recover from won't boot at all on a Nvidia (Mellanox) SN3420.

Step-by-step

Confirm power: PSU LED is green? Cable seated? Wall outlet live?
Try a known-good power cable + outlet.
If the device has multiple PSUs, try with only one PSU at a time.
Connect the console cable and watch for ANY output during power-on.
If completely dark (no LEDs, no console), suspect the PSU or motherboard.
Confirm warranty status, open a Nvidia Enterprise Support case, prepare for an RMA.

CLI / commands

# Verify hardware state
nv show system
nv show platform inventory
nv show platform environment

# Collect for Nvidia Enterprise Support
cl-support (Cumulus) / show techsupport (SONiC)

When to RMA

Repeated failure after re-seat and power-cycle
Visible burn, scorching, or physical damage
POST or memory diagnostic failure
Hardware crashinfo without a software workaround

Frequently asked questions

Will this work on my specific Cumulus Linux / NVOS / SONiC version?

The procedure reflects current Cumulus Linux / NVOS / SONiC behaviour. Older releases may need minor syntax adjustments, use the CLI help (? or tab-completion) to verify.

Should I open a Nvidia Enterprise Support case immediately?

Open one if you suspect hardware failure or the symptom persists after a maintenance-window reload. Make sure your support entitlement is active first.

Where can I find the Nvidia (Mellanox) official documentation?

https://docs.nvidia.com/networking/. search the product family + feature name.

Is this procedure safe in production?

Test in a lab or maintenance window first. Capture pre-change state so you can roll back.

All Nvidia (Mellanox) fix guides → /nvidia/
All vendor guides → /vendors/

Related guides worth a look while you sort this one out:

References

Nvidia (Mellanox) support portal: https://enterprise-support.nvidia.com/
Nvidia (Mellanox) knowledge base: https://docs.nvidia.com/networking/
Nvidia (Mellanox) security advisories: https://www.nvidia.com/en-us/security/
Open a case: https://enterprise-support.nvidia.com/s/createcase

Reference material, not professional advice. Validate against your specific Cumulus Linux / NVOS / SONiC version and test in a non-production environment before applying.

Why this matters for your day-to-day

A Nvidia device that's misbehaving costs more than the fix itself: lost productivity, missed calls, security risk, even safety risk in some categories. Treating the symptom quickly with a documented procedure is cheaper than letting it persist. The steps above are written to get you back to working in under an hour where possible, and to flag clearly when escalation is the right call.

Safety + preconditions

Before any work on a Nvidia device:

Unplug from mains for any internal-access procedure.
Discharge stored energy (capacitors in PSUs, residual battery charge) per manufacturer guidance.
Use ESD-safe handling for boards and modules, no carpet, no wool sleeves.
Avoid moisture; never apply liquids near vents or connectors.
If you smell smoke, see scorch marks, or feel uneven heat, stop and escalate.

Quick verification

Before you walk away from a Nvidia device fix, run through:

1. Reproduce the original trigger: does the issue reappear? 2. Check the device's status / health screen for any new alerts. 3. Confirm paired devices (app, hub, controller) reconnected. 4. Save / commit any configuration changes per the device's normal workflow. 5. Note the change in your maintenance log with date + firmware version.

Escalation guide

For a Nvidia device, the right escalation depends on impact:

Cosmetic / minor: log a ticket via the Nvidia app or web portal. Response 1-3 business days.
Mid-impact: phone support. Have your serial number ready.
Critical (production down, safety issue): in-person dealer / TAC visit. Bring proof of purchase.
Out of warranty: third-party repair shop with manufacturer-certified technicians.