State of the Art Product Testing, Engineering and Support Systems

National Depot Repair is proud of a long history providing excellent product testing and evaluation services to industries served by technology. Our engineering staff bring over 50 year of combined experience performing product testing and evaluation services to our clients

Product Testing services include:

Burn-in Testing

Burn-in testing in an alternative to Environmental Stress Screening (ESS), and is widely used as an aid in producing failure-free electronic components. When scientifically planned and conducted, burn-in-testing offers one of the most effective methods of reliability screening at the component level. By testing individual elements under constant temperature stress, electrical stress, temperature cycling stress, or a combined thermal-electrical stress, burn-in testing can identify discrete faults that may be harder to perceive at the assembly, module, or system level.

Another reason for conducting burn-in tests is when alternate parts are being qualified for use in place of an original part due to obsolescence issues or extended lead times. If the life cycle of the product warrants, the manufacturer may want to qualify additional parts to the design as a second source part in the event of sourcing issues. Burn-in tests are used for this purpose, as well as to qualify alternate parts used in the repair of a product due to increased costs for the original part. In such cases NDR locates, sources, tests and qualifies products for manufacturers utilizing standard engineering practices and approved manufacturer methods.

Environmental and Thermal Testing

Environmental Stress Screening (ESS) is a type of testing conducted through the use of safety equipment called the environmental chamber. The customary use for environmental chambers is to test the thresholds of component parts or full systems. The most common type of environmental chamber is for thermal testing where the part or system is subjected to extremes of both high and low temperatures and humidity fluctuations to determine the effects. Vibration analysis, moisture absorption and stress testing are also common functions of environmental chambers. Many industries have their own specific tests for these functions, such as repetitive motion to test the durability of an item.

A chamber is designed so that extreme fluctuations are possible, in order to put the maximum stress(es) on the product being tested. In addition to measuring temperature, an environmental chamber uses meters and readouts for time, date, humidity, pressure, and more. NDR works in conjunction with a local environmental testing lab as well as with in house developed fixtures. This ensures a full complement of environmental testing fixtures is available for your product.

Parts Screening Services and Testing

Parts manufacturing is a complicated process with many varied requirements and exacting specifications. Despite numerous controls and processes, defects that cause early-life failures can be randomly built into any product. Defects many include imperfections in raw materials, process controls, electrical or electromechanical performance characteristics. Screening tests are designed to be destructive to defective parts and components but nondestructive to fully-functioning parts.

NDR’s product screening services provide a 100% non-destructive screening test on parts that will be used in a manufacturing or repair processes. This service allows manufacturers to feel confident in their critical part usage minimizing the likelihood of early-life failures (commonly referred to as “infant mortality”)

Failure Analysis

Failure analysis is the process of collecting and analyzing data to determine the cause of a product or process failure. The general goal of the analysis is to determine the root cause of a failure and prevent it from recurring. It is an important discipline in many branches of the manufacturing industry, such as the electronics industry, where it is a vital tool used in developing new products and improving existing products. This process relies on collecting failed components or associated data for subsequent examination of the cause(s) of failure using a wide array of methods including: Failure Data Collection, FMECA (Failure Mode, Effects and Criticality Analysis) and FMEA (Failure Mode and Effects Analysis).

Nondestructive testing (NDT) is the process of inspecting, testing or evaluating materials or components. It is an extremely valuable component of failure analysis because after the analysis the part can still be used. NDT methods are typically the starting point of failure analysis and are employed whenever possible.

Another aspect of failure analysis is associated with No Trouble Found (NTF), sometimes referred to as No Fault Found (NFF), which describes a situation where an originally reported mode of failure can’t be duplicated by the evaluating technician and therefore the indicated defect can’t be fixed. NTF can be attributed to oxidation, defective connections of electrical components, temporary shorts or opens in the circuits, software bugs, temporary environmental factors, and operator error.

Functional Testing

NDR offers both forms of functional testing: pre- and post-repair, as well as hardware or software testing. Functional tests are completed on all items repaired at NDR to ensure reliable operation in the field before shipping back to the client. During the post manufacturing phase, many companies outsource their functional testing needs to NDR to validate the functionality of the designed product. We utilize the following practices and sound engineering methodologies to ensure operational success for the manufacturer.

Pre- and post-repair
Functional testing should be completed both before and after a repair to identify problems with the product. Tests are conducted to ensure that the repaired product physically works the way it was intended and that all required software menu options are present and functioning. It also ensures that the product conforms to the industry standards relevant to that environment. In other words, during repairs on imaging products such as copiers, all printed circuit boards are placed back in their operating environment and all functionality is exercised to ensure the success of the repair.

Hardware or software testing
The primary processes and deliverables required for the hardware or software functional test are: Test Planning, Partitioning/ Functional Decomposition, Requirements Definition/ Verification, Test Case Design, Traceability (Traceability Matrix), Test Case Execution, Defect Management, and Coverage Analysis. The processes and deliverables that are applied to any given testing situation are dependent on available resources (people, source materials, time, etc.), the mandate of the test organization, and customer requirements.

During Test Planning, NDR identifies the test equipment needed, scheduling, parts allocation, and other test deliverables. Our Engineers will deliver a test plan (document) and a test schedule (work plan) for evaluation. Test plans often undergo several revisions during the testing cycle due to revisions or more strict requirements.