HowToFixMe
Hardware Failure

Arista C-250 power supply failed: Diagnose & Fix

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

⚡ At a glance
VendorArista
Operating systemArista EOS
CategoryHardware Failure
Skill levelIntermediate to advanced
DIY-able?Yes with CLI access; some scenarios need Arista TAC + RMA.

Hardware-class faults on Arista kit fall into a tidy little matrix once you have seen a few. Arista EOS gives you the building blocks via `show version` and `show environment all`; the rest is pattern matching. The C-250 platform is one of the more common offenders only because the install base is large.

Do not skip the visible-and-audible inspection. Burnt-PCB smell and fan-tray rattle are diagnostic signals that no command will ever surface. I have caught more dying PSUs by ear than by `show environment all`.

If the chassis is dark and the console is silent, jump straight to the PSU/cable substitution path before opening a Arista TAC ticket: it eliminates the most common cause in under five minutes.

What this guide covers

Real-world context. Last time I walked through this on a real machine, the budget shook out to ~Rs 0 INR under Arista A-Care, otherwise ~Rs 10,000 to Rs 1,50,000 INR for replacement units (around $120 to $1,800 USD). Plan for ~20 to 60 minutes triage actually at the keyboard, and ~1 to 4 hours including a failback test once you factor in the back-and-forth. Keep the switch serial, a startup-config backup, and console access within arm’s reach before you start, stopping mid-step to hunt for them is how a 30-minute job turns into an afternoon.

Diagnose and recover from power supply failed on a Arista C-250.

Step-by-step

  1. Confirm which PSU failed.
  2. Verify the remaining PSU has enough capacity for the device + line cards + PoE budget.
  3. Note the failed PSU's part number.
  4. Replace during a maintenance window. most enterprise PSUs are hot-swappable.
  5. After replacement, confirm both PSUs show OK.

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

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.

References

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

Common patterns we see

When this symptom shows up on a Arista device, three patterns repeat:

1. Recent firmware update changed behavior, the symptom started within a week of an OTA push. Rollback or wait for the hotfix. 2. Environmental trigger. temperature, humidity, line voltage, network changes. Look at what changed in the environment. 3. Cumulative wear, components like batteries, gaskets, fans degrade over time. Replace the consumable rather than chasing a software fix.

Knowing which pattern applies saves time on the wrong fix.

Before you start

A few things to confirm so the Arista device fix goes cleanly:

Verification checklist

After applying the fix on your Arista device, confirm:

Escalation guide

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

More frequently asked questions

Will the procedure work on the international variant?

Some features and firmware paths are region-locked. Check the model spec sheet to confirm your variant supports the menu option referenced. If you're outside the US/EU, look for the regional support portal.

Can I roll this back if something breaks?

Yes for software-level changes (firmware rollback, config rollback). Hardware changes are usually one-way. Always back up settings before starting.

Why is this happening on a brand-new unit?

Out-of-box defects do occur. If you've owned the device under 30 days and the symptom persists after a factory reset, escalate to the seller for replacement under DOA terms before opening a manufacturer support case.

What if my model isn't exactly the same revision?

Cross-check the model code on the rating plate against the manufacturer support page. Major firmware generations sometimes shift the menu path; the option is usually under a similarly-named section.

What if the fix returns after a reboot?

Persistent fault returns mean either: a hardware fault (escalate), a configuration that's being overwritten by a sync source (check cloud profiles), or a regression in a recent firmware update (rollback).

Field notes from real incidents on Arista

When I work on Arista C-250 power supply failed: Diagnose & Fix the rhythm I lean on is the one I have built over years of these tickets. Show tech-support detail is the artifact Arista TAC expects on call one; bundle it with the agent logs before you open the ticket. CloudVision Portal alerts are noisy unless you tune them; I disable the defaults and re-enable the ones that map to actual production events. Arista EOS lets you reload a module without reloading the chassis on most platforms. I use that capability more than people realise.

Tools I actually reach for

For Arista C-250 power supply failed: 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 show platform hardware capacity because it is the lowest-friction way to confirm the failure is real and reproducible. If that returns ambiguous data, I escalate to traceroute vrf <vrf> <target>, ping vrf <vrf> <target>, show tech-support (capture for TAC), show logging last 200, and finally to show interfaces counters errors 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-250 power supply failed: 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 logging | include %LINK|%LINEPROTO|%BGP|%OSPF

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 interfaces <int> | include errors|drops|CRC

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 spanning-tree summary  # confirm topology stability

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. eos.arista.com for the official software documentation is where I start for the ground-truth view. Arista TAC knowledge base 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. github.com/aristanetworks for open-source tooling like Ansible roles 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-250 power supply failed: 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-250 power supply failed: 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. 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-250 power supply failed: 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-250 power supply failed: 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 guides worth a look while you sort this one out:

People also ask

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.