[Home](/)/[Resources](/resources)/CE Testing Failures EUTesting Guide # CE Testing Failures: Common Issues and How to Fix Them Complete guide to common CE testing failures. Learn about typical EMC, LVD, and RED failures, their root causes, and how to fix compliance issues. Copy Link[Share on WhatsApp](https://wa.me/?text=https%3A%2F%2Fkrono-labs.com%2Fguides%2Fce-testing-failures) At a glance Common failures 4 FAQs 5 ## Common testing failures EMC emissions ### Radiated or conducted emissions exceed limits Common causes Inadequate filtering, poor PCB layout, missing shielding, long cables acting as antennas Typical fixes Add ferrite beads, improve filtering, add shielding, shorten cables, improve ground plane EMC immunity ### Product malfunctions during immunity testing Common causes Inadequate input protection, poor filtering, susceptible reset circuits Typical fixes Add TVS diodes, improve filtering, add reset circuit protection, shield sensitive circuits LVD dielectric strength ### Insulation breaks down during high-voltage test Common causes Insufficient creepage/clearance, poor insulation material quality, contamination Typical fixes Increase spacing, use better insulation materials, add conformal coating, improve assembly quality LVD temperature ### Components or surfaces exceed temperature limits Common causes Inadequate heatsinking, poor ventilation, overloaded components Typical fixes Add heatsinks, improve airflow, derate components, add thermal protection ## Frequently Asked Questions ### What happens if my product fails testing? The lab will issue a test report identifying the failures. You must address the root causes, implement fixes, and then pay for re-testing. Re-testing typically costs 50-75% of the original test fee. ### Can I negotiate with the lab about failures? Test results are objective measurements based on standards. If you believe there's a test methodology error, discuss it with the lab. However, you cannot negotiate away actual failures — the product must meet the limits. ### How long does it take to fix failures? Simple fixes like adding ferrite beads may take days. Complex issues like PCB redesign may take weeks or months. Plan for potential re-work in your project timeline. Pre-compliance testing helps identify issues early. ### Are some failures more common than others? Yes. EMC emissions failures are very common, especially for products with switching power supplies or high-speed digital circuits. LVD creepage/clearance issues are also common in compact designs. RED failures often relate to spectrum efficiency. ### Can I use test data from a different lab? Generally no. CE marking requires test reports from an accredited laboratory. Test data from non-accredited sources or previous testing at different labs typically cannot be used for formal CE compliance documentation. **Disclaimer:** This page is an educational resource based on official EU sources. It is not legal or engineering advice. Always verify current directive and standard status in the Official Journal before placing any product on the EU market. 🇪🇺 CE Marking roadmap for your product Every standard, document, and test that applies — free, no account required. See your free roadmap[ Want an expert to take your product through 🇪🇺 CE Marking compliance for you? One consultant from Krono's compliance team takes your product from requirements to legal sale, with a fixed quote before any work starts. See compliance services](/services) Learn this properly In-depth course that teaches the full process, not just this one answer. [Start the course — $149](/courses/01-ce-marking-for-electronics-engineers)[Prefer to read? Get the book — $24.99](/books/01-ce-marking-for-electronics-engineers) Related guides * [CE EMC testing requirementsComplete guide to EMC testing for CE marking.](/guides/ce-emc-testing-requirements) * [CE LVD testingComplete guide to LVD testing for CE marking.](/guides/ce-lvd-testing) * [How to prepare for CE testingComplete guide to preparing for CE testing.](/guides/how-to-prepare-for-ce-testing) * [CE testing costsComplete guide to CE testing costs.](/guides/ce-testing-costs)