(more than 100Vdc due to limitation of voltage that is provided) or AC equipment Source those have interface to PC as the ICT Controller Bead probe technology to access small traces that cannot be accessed by traditional means Limitations While in-circuit test is a very powerful tool for testing PCBs, it has these limitations: Parallel components can often only be tested as one component if the components are of the same type (i.e. two resistors); though different components in parallel may be testable using a sequence of different tests - e.g. a DC voltage measurement versus a measurement of AC injection current at a node. Electrolytic components can be tested for polarity only in specific configurations (e.g. if not parallel connected to power rails) or with a specific sensor The quality of electrical contacts can not be tested unless extra test points and/or a dedicated extra cable harness are provided. It is only as good as the design of the PCB. If no test access has been provided by the PCB designer then some tests will not be possible. See Design For Test guidelines. Related technologies The following are related technologies and are also used in electronic production to test for the correct operation of Electronics Printed Circuit boards: PCB electrical test of bare PCBs AXI Automated x-ray inspection JTAG Joint Test Action Group (Boundary Scan Technology) AOI automated optical inspection Functional testing (see Acceptance testing and FCT) References External links In-Circuit Test Tutorial Printed circuit board manufacturing Hardware testing Electronic test equipment