How to Spot Counterfeit Automation Parts (and Avoid Them)

Counterfeit automation parts have quietly become one of the most expensive hidden threats in modern manufacturing. As tariffs, long OEM lead times, and discontinued legacy models push plants toward alternative suppliers, the risk of accidentally purchasing a fake PLC, drive, HMI, or servo component increases dramatically.

These counterfeits aren’t always easy to spot — some look nearly identical to the real thing. But they rarely hold up in actual production environments. They fail faster, behave unpredictably, corrupt logic, overheat quickly, and can damage equipment downstream.

This guide explains how to identify counterfeit automation parts with confidence, using clear technical indicators and realistic examples you can apply immediately.

Why Counterfeit Parts Are a Growing Problem

Counterfeits thrive in markets experiencing:

• High global demand
• Tariffs or regional restrictions
• Long OEM lead times
• Discontinued or obsolete components
• Heavy reliance on online resellers

In 2024–2025, all five pressures converged for industrial automation.

This has squeezed availability for brands like:

• Siemens
• Mitsubishi
• Yaskawa
• Schneider
• FANUC
• Delta Electronics
• ABB
• Omron

When buyers can’t wait weeks or months for OEM stock, counterfeiters exploit the situation by offering “too good to be true” deals with convincing photos and vague listings.

The 8 Most Common Signs of Counterfeit Automation Parts

Below are the most common warning signs, with conceptual examples to make them easier to recognize.

1. Suspiciously Low Pricing

Counterfeiters almost always use aggressive pricing to lure buyers.

Conceptual example: A Siemens PLC power supply normally lists around $340–$375 for refurbished condition. A seller offering a “brand-new OEM unit” for $89 is not operating legitimately.

OEM components contain proprietary chips, high-quality capacitors, and specific plastics. These cannot be manufactured cheaply without drastically reducing quality — which is exactly what counterfeiters do.

If a price is more than 40–60% below normal market value, treat it as a high-alert item.

2. Incorrect or Inconsistent Labeling

Authentic automation parts use extremely specific labeling:

• Exact OEM font families
• Precise spacing between letters and numbers
• Correct CE/UL markings
• Accurate catalog numbering structure
• Serial numbers that match known OEM patterns

Conceptual example: A Siemens CPU label may have slightly heavier font weight, or the QR code may be misaligned or blurry. Real OEM labels never have smudging, shadowing, or print variation — they are printed with high-precision industrial printers.

Two major giveaways include:

• Stickers placed at slight angles
• Holographic seals that look flat instead of textured

If a label looks like it was printed on a low-cost office printer, assume it’s not genuine.

3. Wrong Screws, Plastics, or Enclosures

OEMs use consistent materials — down to screw types, textures, resin blends, and enclosure patterns.

Counterfeits often show:

• Plastic that feels soft, thin, or overly shiny
• Screws with mismatched heads or incorrect thread depth
• Covers that flex too easily
• Inconsistent color between pieces

Conceptual example: A Mitsubishi servo amplifier normally uses a specific silver or matte-black heat sink. Counterfeit versions often have heat sinks with a different shade, cheaper metal finish, or sharp, bent edges.

A real OEM enclosure will always feel sturdy and cohesive. If something feels “off” in your hand, it usually is.

4. Missing or Invalid Serial Numbers

OEM serials follow standardized logic — including checksum formats, batch location codes, and internal date patterns.

Counterfeits often contain:

• Serial numbers that appear random
• Duplicate serials across multiple units
• Serial stickers with different font sizes
• Numbers that don’t match the product generation

Conceptual example: Two “new” Yaskawa servo drives showing the exact same serial number sequence — impossible under true OEM manufacturing.

If the seller cannot explain serial mismatches, walk away.

5. Bad Firmware, OS, or Configuration Behavior

This is where counterfeits are easiest to expose — they cannot replicate the OEM’s firmware perfectly.

Common signs include:

• Firmware version that doesn’t exist according to documentation
• PLC modules that fail to identify in TIA Portal, GX Works, or Sysmac Studio
• HMIs that boot with missing menus or inconsistent graphics
• Drives that trip under minimal load
• Servo amplifiers that cannot tune correctly
• Communication buses that fail intermittently

Conceptual example: A counterfeit Siemens I/O module may appear fine physically, but the moment it’s added to a rack, the PLC flags it as an unsupported device.

Hardware can be copied. Firmware cannot.

6. Used Parts Sold as “New”

Some counterfeiters refurbish used parts, re-label them, and sell them as new.

Watch for:

• Scratches or tool marks
• Mounting bracket wear
• Yellowing or discoloration
• Dust inside fan vents
• Inconsistent sealant on covers

Conceptual example: A “new” HMI with visibly polished screw heads or a faint outline where old labels were removed.

If the condition feels like “lightly used” rather than “factory fresh,” it’s not new.

7. No Warranty or Very Short Warranties

Legitimate suppliers stand behind their testing and authentication.

Reputable resellers typically offer:

• 12+ months for refurbished condition
• 24+ months for verified replacements
• Clear return and exchange policies

Counterfeit sellers usually offer:

• 7–30 day warranties
• No written documentation
• “Final sale only” disclaimers
• No ability to provide test reports

A short warranty is often the clearest indication the seller knows the part won’t last.

8. Marketplace Sellers With No History

Counterfeits frequently appear on platforms where seller identity is easy to hide:

• eBay
• AliExpress
• Facebook Marketplace
• Amazon third-party sellers

Conceptual example: A seller who joined eBay three weeks ago, has two reviews, and is selling 50+ Siemens CPUs — that inventory level does not align with a new account.

Always evaluate:

• Account age
• Feedback depth
• Sales history
• Location consistency
• Whether the seller is a real business with accessible staff

If the profile looks disposable, assume the products are too.

How to Verify a Part Before You Buy

These steps let you authenticate most components with high confidence.

1. Request Real Photos, Not Stock Images

Ask the seller to provide photos showing:

• All sides of the component
• Label close-ups
• Terminal connection condition
• Screw heads and heat sink edges
• Any seals or markings
• The box and packaging

Real photos reveal minor details counterfeits cannot hide.

2. Ask for Functional Test Proof

A legitimate supplier can provide:

• Power-on test confirmation
• Drive load test results
• PLC I/O scan verification
• HMI interface responsiveness checks
• Communication test logs
• Servo tuning verification

You don’t need formal case studies — just proof the part was powered, scanned, and evaluated.

3. Verify the Warranty

Counterfeiters will never offer a 12–24 month warranty — the parts fail too quickly.

Industrial Automation Co. provides a 24-month warranty because every component is authenticated and tested before shipping.

Strong warranties are a reliable trust indicator.

4. Check the Seller’s History

Look for:

• Long-term domain presence
• Actual staff and a physical warehouse
• Customer service reachable by phone or email
• Detailed product pages
• Industry specialization

Counterfeiters avoid operational transparency because it exposes them.

5. Confirm Packaging Standards

OEM packaging is extremely predictable:

• Precise foam cutouts
• Anti-static bags with correct printing
• Unique barcode placements
• Date codes aligned with product generation
• Tamper-evident seals

Generic boxes, plain bubble wrap, or loose packing are clear signs of reboxed or counterfeit items.

What Happens When Counterfeit Parts Get Installed

Counterfeit automation components create more than just a bad part — they create system-wide risk.

Common failures include:

• Inconsistent voltage regulation
• Poor grounding causing communication noise
• Incorrect sensor readings due to cheap internal chips
• PLC logic faults caused by unreadable I/O
• Drives overheating due to substandard heat sinks
• Servos losing position because of inaccurate encoders

Because automation components interact with larger systems, one fake module can trigger:

• Line stoppages
• Inaccurate batching
• Over-travel in servo applications
• Unexpected motor trips
• Fault cascades across multiple axes

Even a small counterfeit input module can produce bad values that propagate through an entire process.

How Industrial Automation Co. Protects You From Counterfeit Risk

Your plant can’t afford to gamble on automation components. That’s why every part we ship runs through multiple layers of authentication:

• Precise visual inspection
• OEM-label verification
• Serial validation when applicable
• Load testing, tuning, or power-on testing
• Internal quality control documentation
• A 24-month warranty for peace of mind
• Same-day fulfillment from our North Carolina warehouse

We carry genuine parts from Siemens, Mitsubishi, Yaskawa, FANUC, ABB, Schneider, Omron, Delta, and other trusted brands — with testing to match.

Your Final Checklist

Train your team to use this quick decision flow before purchasing or installing critical parts:

• Does the price align with known market ranges?
• Does the label look OEM-accurate?
• Do the plastics and screws match known standards?
• Does the serial number follow expected formatting?
• Does the vendor offer real testing documentation?
• Does the part behave correctly when powered or scanned?
• Does the warranty indicate real confidence in the product?
• Does the seller have a verifiable reputation?

If two or more checks fail, consider the part high-risk.

Need Help Verifying a Part or Finding a Trusted Replacement?

If you’re unsure about a part’s authenticity — or need a genuine replacement fast — our technical team can help inspect, verify, or source exactly what you need.

Reach out anytime