Quality Control Checklist for LED Therapy OEM Orders: The Complete Guide

Pre-Production Quality Planning

Complete these steps before your first production unit rolls off the line.

Product Specification Review

Before production begins, confirm:

[ ] All product specifications are documented in writing

[ ] Specification includes: dimensions, weight, materials, colors, LED wavelengths, LED count, power density, battery capacity, certifications

[ ] Sample approval: you have approved a golden sample (reference unit) that defines acceptable quality

[ ] Golden sample is physically marked and retained for comparison

[ ] Acceptable quality limits (AQL) are defined for each inspection point

Factory Qualification

Before placing orders with a new factory:

[ ] Factory has visited your target market’s certifications (ISO 13485 for medical, ISO 9001 for general)

[ ] Factory has produced similar products before (request references)

[ ] Factory has adequate quality control staff and equipment

[ ] Factory’s quality manual and procedures are documented

[ ] Factory accepts your quality requirements in writing

First Article Inspection (FAI) Protocol

FAI is mandatory for any new product, new supplier, or significant change to existing product:

[ ] Factory conducts FAI on first 5-10 units

[ ] FAI units are tested against all specifications

[ ] FAI results documented with measurements and test data

[ ] You receive FAI report before production approval

[ ] Any FAI failures are corrected before production approval

Incoming Inspection (Component Level)

Not all components need incoming inspection, but critical components do.

Components Requiring Incoming Inspection

[ ] LED chips (wavelength, forward voltage)

[ ] LED drivers (output current, efficiency)

[ ] Batteries (capacity, safety)

[ ] PCBs (visual inspection, continuity test)

[ ] Housing materials (material verification, dimensions)

LED Chip Inspection Protocol

For every new LED batch from any supplier:

[ ] Sample 10 LEDs from the batch

[ ] Measure forward voltage at rated current (spec: X.XV ± tolerance)

[ ] Measure dominant wavelength using spectrometer (spec: XXXnm ± Xnm)

[ ] Measure luminous intensity (spec: X mcd ± tolerance)

[ ] Document batch number and supplier lot code

[ ] Record test results in incoming inspection log

Acceptance criteria: If any sample fails specification, reject the batch and request replacement.

LED Driver Inspection Protocol

For every new LED driver batch:

[ ] Sample 5 drivers from the batch

[ ] Test output current at input voltage range (12V, 15V, 24V)

[ ] Verify output current is within ±5% of specification

[ ] Test efficiency at full load (spec: >X%)

[ ] Verify protection features (over-current, over-voltage protection)

[ ] Run 24-hour burn-in test on sample units

Battery Inspection Protocol

For every new battery batch (battery-powered devices):

[ ] Sample 3 batteries from the batch

[ ] Full charge/discharge cycle to measure actual capacity

[ ] Verify capacity is within -10% of rated capacity

[ ] Check for physical damage (swollen, punctured, discolored)

[ ] Verify manufacturer markings match documentation

[ ] Check safety certifications match order specification

During Production Inspection

Don’t wait until production is complete to check quality. Inspect during production.

Production Monitoring

At least once during production of each batch:

[ ] Visit factory or request video inspection of production line

[ ] Verify production is following approved work instructions

[ ] Check component usage matches BOM (are correct LEDs being used?)

[ ] Verify assembly process matches golden sample

[ ] Document production status and any observations

Inline Testing

For LED therapy devices, these inline tests are critical:

LED functionality test:

[ ] Every unit is powered on and all LEDs illuminate

[ ] No dead LEDs (100% pass rate)

[ ] Wavelength appears correct (visual check with spectrometer if available)

Power and charging test:

[ ] Device charges from low battery to full charge

[ ] Charging indicator functions correctly

[ ] Battery life meets specification

Safety test (where applicable):

[ ] Dielectric strength test (for Class II devices)

[ ] Earth continuity test (for Class I devices)

[ ] Leakage current test

Pre-Shipment Inspection (Final Inspection)

Final inspection happens when production is complete, before goods leave the factory.

Inspection Sampling Plan

Use ANSI/ASQ Z1.4 (formerly MIL-STD-105E) sampling plan:

Normal inspection, Level II is standard for most inspections

AQL for critical defects: 0.0 (zero tolerance)

AQL for major defects: 1.0

AQL for minor defects: 2.5

For a production lot of 3,000 units, Level II normal inspection requires sample size of 200 units.

Visual Inspection Criteria

Major defects (AQL 1.0):

[ ] Visible scratches or dents on housing

[ ] Misaligned components or uneven assembly

[ ] Incorrect color or finish

[ ] Missing components (missing cap, missing button)

[ ] Visible LED misalignment or uneven spacing

[ ] Incorrect or missing branding/labeling

Minor defects (AQL 2.5):

[ ] Minor surface blemishes (visible at >30cm)

[ ] Minor color variation within tolerance

[ ] Minor tool marks not visible at normal viewing distance

[ ] Minor assembly variation not affecting function

Functional Testing Protocol

Every sampled unit undergoes:

LED output test:

[ ] All LEDs illuminate when powered

[ ] No flickering or intermittent operation

[ ] Light output appears uniform across treatment surface

[ ] Mode switching works (if applicable)

[ ] Timer functions correctly

Power test:

[ ] Device turns on and operates from battery

[ ] Battery indicator functions correctly

[ ] Device operates for specified duration on full charge

[ ] Charging system functions correctly

Safety test:

[ ] No unusual heat generation during operation

[ ] No unusual noise during operation

[ ] Housing integrity maintained during operation

Labeling and Packaging Inspection

[ ] Product label present and correct (model number, voltage, certifications)

[ ] CE/FCC/FDA marks present where required

[ ] User manual present and matches product

[ ] All accessories included per specification

[ ] Packaging matches approved sample

[ ] Shipping carton is adequate for transport

[ ] Carton labeling is correct (address, quantity, etc.)

Documentation and Reporting

Every inspection requires documentation.

Required Inspection Documents

Incoming inspection report:

Date of inspection

Component/supplier information

Sample size inspected

Number of defects found

Disposition (accept, reject, accept with conditions)

Inspector name

During production report:

Date of visit/inspection

Production status

Issues observed

Corrective actions taken

Next inspection scheduled

Final inspection report:

Date of inspection

Factory and production batch information

Sampling plan used

Inspection results by category

Defects found with descriptions

Pass/fail determination

Inspector name

Certificate of Conformance

Factory should provide a Certificate of Conformance (COC) with each shipment:

[ ] Confirms products meet all specifications

[ ] Lists any deviations from specification with explanations

[ ] Lists batch/lot numbers for major components

[ ] Signed by factory quality manager

Handling Inspection Failures

When inspection reveals problems, the response depends on severity.

Critical Defect Found (Zero Tolerance)

A critical defect (safety issue, complete non-function) found during any inspection:

Stop production immediately

Quarantine all completed units

Identify root cause with factory

Implement corrective action

Re-inspect all affected units

Do not ship until verified as acceptable

Major Defect Rate Above AQL

If major defect rate exceeds 1.0% (AQL):

Factory must sort 100% of affected lot

Factory implements corrective action

Re-inspect at increased sample size (tighter inspection)

Accept only after passing reinspection

Minor Defect Rate Above AQL

If minor defect rate exceeds 2.5%:

Discuss with factory

Factory may sort or may be accepted as-is depending on nature of defects

Document acceptance in writing

Track minor defect trends over time

The Quality Control Culture

Checklists are only as good as the culture that implements them.

Factory relationship: Quality control works best as a partnership, not a confrontation. Share data with factories. Help them understand what you’re seeing. Work together on root cause analysis.

Supplier accountability: Use quality data to hold suppliers accountable. If Supplier A’s components consistently generate complaints while Supplier B’s don’t, Supplier A costs more than their price suggests.

Continuous improvement: Quality standards should increase over time. Each inspection should improve the next. Track trends, not just individual inspections.

The brands that consistently ship high-quality products are the ones that take quality control seriously — not as an interruption to production, but as an integral part of it.