What testing PCB prototypes actually includes

“Tested” should tell you which board was checked, under what conditions and against which limits. A power LED turning on answers one narrow question. It does not establish that a sensor is accurate, a communication interface handles errors or an enclosure stays within its thermal limits.

For Ohmbo prototype orders, testing follows a written plan, agreed test firmware and acceptance criteria, with a report for each board. Define that plan before fabrication so the design includes the connections and access needed to execute it.

Distinguish the evidence

A design-rule report describes checks on design files. An assembly inspection concerns the populated board. Functional testing exercises specified behavior using power, firmware, inputs and loads. These are related activities, but one record cannot stand in for all three.

This distinction is also relevant when comparing suppliers. JLCPCB's functional-test service describes powered verification using a customer-provided procedure and identifies it as an option for Standard PCBA. A supplier offering assembly may therefore also offer functional testing; the useful question is what your order actually includes. Source checked: 2026-10-19.

Agree on the plan before the boards arrive

A repeatable plan needs:

• The board revision, BOM revision and individual board identifiers.
• The supply settings, current limit, connections, loads and relevant environment.
• Instrument and fixture identifiers, including any reference required for a measurement.
• The test-firmware version, programming method and expected startup behavior.
• Ordered steps with an observable result, units, limits and duration where needed.
• A rule for failures, interrupted tests, rework and retesting.

Assign who supplies the firmware, peripherals and fixtures, and who approves the acceptance limits. Do not assume that production application firmware is a suitable test program. A test build may need a repeatable output or a way to isolate an interface.

Illustrative plan and unexecuted record

This fictional example describes a low-voltage sensor board powered from 5 V. Its proposed limits are examples only, subject to design review. No board has been measured, and none of the rows is a pass result.

Check	Illustrative method and acceptance criterion	Recorded result
Power rail	Measure the specified 3.3 V test point at the agreed load; proposed range 3.20–3.40 V	Not run
Firmware loading	Load the approved test build through the designated programming connection; verify build identifier	Not run
Sensor communication	Request the selected sensor's documented identity; compare with the value in the approved plan	Not run
Fault reporting	Disconnect the sensor using the approved procedure; require an explicit error within two seconds	Not run
Restart	Perform five controlled power cycles; require startup and the expected status on every cycle	Not run

The final plan must specify the exact sensor, fixture, load and firmware. A valid sensor identity proves communication with that device; it does not prove measurement accuracy. Accuracy testing would require an appropriate reference and a separate acceptance criterion.

Request a report for every board

For a five-board order, use five identifiable records. Each should link the board to its test-plan revision, firmware, date, operator, conditions and results. Numeric checks should retain measured values with units, not only a green status. Skipped steps should state why they were skipped.

If a board fails, retain the initial result, record any rework and link the subsequent test. A batch summary can help you scan the outcome, but it should not hide which board was retested or which function remains unverified.

Keep claims within the test boundary

A short functional check does not establish long-term reliability, environmental performance, regulatory compliance or suitability for a safety-critical application. Ask for additional work to be scoped explicitly rather than reading it into the word “tested.”

Confirm the included checks and any fixture requirements through pricing and the order process. Keep the reports with your design and manufacturing files. The board library currently presents design demonstrations; those illustrations do not supply physical test evidence.