Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix

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

What this guide covers

Diagnose and recover from smoke smell or burned PCB on a Arista C-200 (acquired Mojo).

Full fix path

1. STOP. Power off the device at the wall before touching it.
2. Open the chassis and identify which board / module is the source of the smell.
3. Photograph the visible damage (scorched capacitors, blackened ICs).
4. Note the device serial number and exact model for the support case.
5. Do not power back on, burned components fail closed and can damage adjacent boards.
6. Open a Arista TAC case with the photos and serial.
7. RMA the affected component (line card, supervisor, PSU) or the full chassis if the backplane is damaged.

CLI / commands

# Verify hardware state
show version
show inventory
show environment all

# Collect for Arista TAC
show tech-support | redirect file:show-tech.log

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 Arista EOS version?

The procedure reflects current Arista EOS behaviour. Older releases may need minor syntax adjustments: use the CLI help (? or tab-completion) to verify.

Should I open a Arista TAC 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 Arista official documentation?

https://www.arista.com/en/support/toi, 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.

Related guides

• All Arista fix guides → /arista/
• All vendor guides → /vendors/

References

• Arista support portal: https://www.arista.com/en/support
• Arista knowledge base: https://www.arista.com/en/support/toi
• Arista security advisories: https://www.arista.com/en/support/advisories-notices
• Open a case: https://www.arista.com/en/support/customer-support

Reference material, not professional advice. Validate against your specific Arista EOS version and test in a non-production environment before applying.

Why this matters for your day-to-day

A Arista 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 Arista 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.

Confirm it stuck

On a Arista device, the test is rarely "reboot and see". Use this list:

• Active reproduction: trigger the original failure path on purpose.
• Indirect reproduction: do an activity that would expose the same subsystem.
• Status indicator review: every LED / display / app status should be green.
• 24-hour soak: leave the device under normal load overnight; check the next morning.
• Telemetry check: review the device or app's diagnostic log for new error entries.

Escalation guide

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

• Cosmetic / minor: log a ticket via the Arista 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.

More frequently asked questions

Does this affect other devices on my network?

Generally no. The procedure is local to this device. Network-side changes (firmware updates that affect TLS, SMB, or routing) are flagged explicitly in the steps.

Is it safe to apply during business hours?

If the device is in production use, apply during a scheduled maintenance window. Most procedures need 2-15 minutes of downtime. Capture pre-change state so you can roll back if needed.

How long does this fix usually take?

Most users complete the steps in 20-45 minutes the first time, and 5-10 minutes on subsequent runs once the menu paths are familiar.

Will this void my warranty?

Applying official firmware updates and following the user manual will not affect warranty. Opening sealed components, jumping safety circuits, or using third-party parts can void warranty in most jurisdictions.

Should I update firmware first or last?

Update firmware first if a release note specifically mentions your symptom. Otherwise, finish the troubleshooting flow first, then update; that way you can isolate whether the update or the underlying fix solved it.

Field notes from real incidents on Arista

When I work on Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix the rhythm I lean on is the one I have built over years of these tickets. EOS-API (eAPI) over HTTPS is the cleanest way to script Arista at scale; do not wrap CLI screen-scraping when eAPI returns JSON. Arista EOS lets you reload a module without reloading the chassis on most platforms, I use that capability more than people realise. Show tech-support detail is the artifact Arista TAC expects on call one; bundle it with the agent logs before you open the ticket.

Tools I actually reach for

For Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix on Arista the cheapest signal I can land usually comes from a known order of operations, not a kitchen-sink approach. I start with packet capture on the ingress interface (TAC will ask for it) because it is the lowest-friction way to confirm the failure is real and reproducible. If that returns ambiguous data, I escalate to show platform hardware capacity, show tech-support (capture for TAC), and finally to show running-config | include <feature> only when the cheaper tools cannot reach the layer the failure lives in. That ordering matches the failure surfaces I have actually seen on Arista units over the last few years, not an abstract taxonomy. The cheap signals gate the expensive ones so the investigation does not balloon into a multi-hour exercise.

Verification I run before I close the ticket

Before I mark Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix resolved on a Arista unit, the verification loop below is what I actually run. Each step proves a different layer is green, and the order matters - the cheap checks gate the more expensive ones so I never burn an hour on a deep test that a shallow one would have failed in seconds.

show bgp summary  # confirm session state after route changes

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

show ip route <prefix>  # confirm best path post-change

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

show logging | include %LINK|%LINEPROTO|%BGP|%OSPF

Only when every line above runs clean do I close the ticket and update the runbook with the timestamps. A green verification that nobody can reproduce is not a fix, it is luck waiting to regress.

Where I check first when the docs disagree

When two sources contradict each other on a Arista detail, the disambiguation order I lean on is stable across products and across years. Arista TAC knowledge base is where I start for the ground-truth view. github.com/aristanetworks for open-source tooling like Ansible roles is where I start for the ground-truth view. arista.com/en/support/product-documentation for EOS command references is where I start for the ground-truth view. Random blog posts and reseller wikis are signal, not ground truth, and I treat them as such until the references above either confirm or contradict the claim. The cost of trusting an unauthoritative source on Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix is rarely worth the time it saved.

Pitfalls I have walked into on this exact path

The shortcuts that look smart on Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix have a habit of biting back. The pitfalls below are the ones I have personally walked into on a Arista unit, not things I read about. Show tech-support detail is the artifact Arista TAC expects on call one; bundle it with the agent logs before you open the ticket. EOS-API (eAPI) over HTTPS is the cleanest way to script Arista at scale; do not wrap CLI screen-scraping when eAPI returns JSON. CloudVision Portal alerts are noisy unless you tune them; I disable the defaults and re-enable the ones that map to actual production events. When in doubt I revert to the slower path that the manual prescribes - the time I save by skipping it is always smaller than the time I spend cleaning up afterwards.

What I tell the next on-call

When I hand Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix off to the next person on rotation, the three lines I leave in the runbook are these. First, the symptom signature on Arista - not a paraphrase, the exact string that surfaces in logs or on the screen. Second, the diagnostic that gave the highest signal in the least time. Third, the exact verification command whose green output justified closing the ticket. That trio is what turns a one-off fix into a runbook entry the next engineer can use without paging me at three in the morning.

I also add a one-line note on the cost of getting this wrong. For Arista C-200 (acquired Mojo) smoke smell or burned PCB: Diagnose & Fix on a Arista unit, the cost is rarely the replacement part or the patch itself. It is the downtime, the second site visit, and the trust deficit you spend with whoever owns the asset when the fix does not hold. That framing keeps the next on-call from choosing the cheap-looking shortcut that ends up costing the most in elapsed hours and goodwill.

Related fixes

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

• Arista 7010T smoke smell or burned PCB: Diagnose & Fix
• Arista 7050X3 smoke smell or burned PCB: Diagnose & Fix
• Arista 7060X4 smoke smell or burned PCB: Diagnose & Fix
• Arista 7060X5 smoke smell or burned PCB: Diagnose & Fix
• Arista 7060X6 smoke smell or burned PCB: Diagnose & Fix
• Arista 7280R smoke smell or burned PCB: Diagnose & Fix