Independent suppliers are often the only realistic source for discontinued or hard-to-find automation parts — but the gray market also attracts counterfeit and mislabeled components. Before you wire money for any PLC module, HMI or servo drive, work through this checklist.
1. Check the label quality and print
Genuine manufacturer labels have crisp, consistent print, correct font spacing and no smudging. Fakes often show blurry logos, uneven serial number stamps, or labels that peel too easily. Cross-check the part number format against the manufacturer's datasheet.
2. Verify the serial number traceability
Ask the supplier for serial numbers before payment. Major manufacturers (Siemens, Allen-Bradley/Rockwell, Omron) can trace production date codes from serial numbers. A supplier who refuses to share serials is hiding something.
3. Ask for photos of the actual unit
Stock photos are fine for listings, but before purchase request photos of the specific unit: full face, label close-up, connectors, and any scratches. This takes the supplier 2 minutes and tells you the part actually exists in their warehouse.
4. Confirm condition category in writing
"Used" can mean anything from "pulled from a running line last week" to "sat in a damp warehouse for a decade". Get the condition defined: New in Box (NIB) / New Open Box / Refurbished / Pulled-Working / Pulled-Untested. Require it on the invoice.
5. Request test or inspection records
For refurbished and pulled parts, professional suppliers keep inspection records: I/O point testing, communication port checks, or bench verification. If a supplier claims a part is "tested", ask what the test covered.
6. Check the warranty terms
A warranty shorter than the time it takes to install, commission and shake down the part is nearly worthless. Look for at least 12 months, and confirm the warranty covers replacement, not just "repair evaluation".
7. Evaluate how the supplier communicates
Counterfeit sellers are vague and push for fast payment. Legitimate suppliers answer technical questions, provide datasheets, discuss your application, and don't pressure you on timelines. Trust the signals from the conversation — they predict the transaction better than any website design.
What SHLY-PLC provides on every order
Before you order, we will confirm product condition, included accessories and available inspection or test records. Every part ships with a 12-month seller warranty, and our team provides technical selection support for US and Canada customers. If a part raises questions during verification, we resolve it before it becomes your downtime.
Questions about a specific part? Contact us or browse the catalog.