| Flying-probe test | Bare PCB | Check electrical connections without a dedicated fixture | Opens, shorts, and selected net or component values, depending on the test program | Useful for prototypes and low-to-medium volumes; test time can be longer than fixture-based testing. |
| Fixture-based continuity test (bed of nails) | Bare PCB | Test many designated electrical points using a custom fixture | Unintended opens and shorts between tested points | A dedicated fixture is required; it is generally suited to repeat production runs. |
| Netlist comparison | Bare PCB | Compare measured electrical connections with the intended design data | Missing, added, or incorrectly connected nets covered by the test setup | Results depend on accurate design data and adequate access to test points. |
| Insulation-resistance test | Bare PCB | Assess electrical insulation between specified conductors | Insulation resistance below the specified acceptance limit | Test voltage, duration, conditioning, and acceptance criteria should follow the applicable specification. |
| Dielectric-withstand (hipot) test | PCB or assembly, when specified | Verify insulation withstands a prescribed voltage stress | Breakdown or excessive leakage under the defined test conditions | Not interchangeable with a simple continuity test; inappropriate settings can damage a product. |
| Four-wire (Kelvin) resistance measurement | Bare PCB or assembly | Measure low resistance while reducing lead and contact resistance effects | Resistance of selected traces, vias, joints, or other conductive paths | Requires suitable access points and a defined measurement method. |
| Controlled-impedance measurement | Bare PCB, typically with test coupons | Check whether selected transmission structures meet specified impedance requirements | Impedance of designated traces or coupons using an appropriate measurement method | Coupon design, stack-up, and measurement method affect how representative the result is of the board. |
| Time-domain reflectometry (TDR) | Bare PCB or interconnect | Analyze impedance changes along a transmission path | Locations of impedance discontinuities, subject to instrument setup and resolution | Requires appropriate fixtures, calibration, and interpretation of the waveform. |
| In-circuit test (ICT) | Assembled PCB | Test accessible components and electrical nodes on a populated board | Selected assembly faults, such as shorts, opens, and incorrect or out-of-limit components | Coverage depends on test-point access, fixture design, and the test program. |
| Functional test | Assembled PCB or finished product | Operate the product or board under defined inputs and conditions | Whether tested functions and interfaces behave as specified | Complements structural tests; results are limited to the functions and conditions included in the test. |