A useful return material authorization (RMA) request describes a reproducible failure and the tests that separate the transceiver from the host, configuration and fiber path. “Module does not work” creates delay for both the operator and supplier. Preserve the original evidence, isolate the fault safely and submit the smallest complete package needed for a decision.

Identify the exact affected unit

Record supplier and internal part references, form factor, application, wavelength or BiDi side, coding profile, serial number, lot/date code and purchase order. Photograph the label when appropriate.

State the installation date, endpoint, port and service role. If several units are involved, list each serial separately. Do not combine different symptoms or batches into one undefined failure count.

Capture the host and software context

Provide the exact device, chassis, line card or adapter, port, software or firmware and configured speed/mode. Include relevant FEC, breakout, autonegotiation and supported-optics settings.

Save the complete warning or alarm rather than paraphrasing it. A module absent from inventory, rejected by policy, accepted with no link and flapping under traffic are different cases.

The SFP detected but link down guide provides a structured first-pass symptom classification.

Preserve optical and error evidence

Record transmit and receive power, temperature, voltage, laser bias, diagnostic thresholds and timestamp where the host exposes them. Capture both endpoints and both directions.

Add interface state, FEC, lane, physical-layer and packet error counters. Save the values before clearing them. Note traffic conditions and the observation period.

Diagnostic data can support a failure claim, but it does not automatically establish root cause. Missing DOM may reflect platform support or a management-interface problem.

Isolate the path and configuration

Confirm that the intended module pair, wavelength, fiber type, connector, polarity, route and attenuation match the application. Inspect and clean connectors under the approved procedure. Verify port configuration and host support.

If the issue follows recent maintenance or a software update, record the timeline. Do not hide changes that may be essential to reproduction.

Use controlled substitution

When safe and permitted, replace one variable at a time with a verified known-good component. Record the serial and test result.

• Suspect module fails in a known-good port while a verified module passes: stronger module evidence.
• Failure remains on the original path with a verified module: investigate host, configuration or fiber.
• Failure follows one jumper or passive route: investigate the path.
• Unit is rejected only by one host/software combination: investigate coding and platform support.

A substitution is not conclusive if the replacement has a different application, coding or power range.

Describe intermittency precisely

For intermittent faults, provide start time, duration, frequency, temperature, traffic, alarms and environmental conditions. Include whether a reseat or cool-down temporarily restores operation.

Avoid statements such as “fails sometimes.” A timeline and counter trend can show whether the fault is thermal, path-related, configuration-dependent or random.

Package and return without creating new damage

Follow handling instructions, install protective caps and use suitable electrostatic-discharge packaging. Identify the unit and RMA reference without covering required labels. Keep physically damaged, contaminated and electronically failed units separate.

Submit the evidence package before shipping when possible. The supplier may request a targeted command, host retest or photograph that prevents an unnecessary return.

Frequently asked questions

Is a link-down screenshot enough for an RMA?

Usually not. Include identity, host context, configuration, alarms, diagnostics, counters and isolation steps.

Does swapping the module prove it is faulty?

It is strong evidence only when the replacement is verified, equivalent and tested while other conditions remain unchanged.

Should counters be cleared before collecting evidence?

Save the original values and timestamps first. Clear only as part of a controlled test.

What if the failure occurs on only one software release?

Record both working and failing releases and exact host behavior. The issue may involve support or coding rather than physical damage.

Can a dirty connector cause an unnecessary RMA?

Yes. Follow the approved inspection and cleaning procedure and record the before-and-after result.

Should a failed BiDi module be returned with its pair?

Follow the supplier process. Always identify both complementary wavelengths and the counterpart used in testing.

Reduce RMA delay with reproducible evidence

Share the part identity, host/software context, serials, alarms, DOM, counters, route and controlled substitutions. Axonode can coordinate troubleshooting evidence, traceability and return handling for optics supplied through the project.

Contact Axonode for transceiver support and review the optical transceiver portfolio.