Cage Blocks hold UUT for probing.

Cage Blocks hold UUT for Probing

When tooling holes are not available, Cage Blocks are a simple way to capture the PCB so it can be probed.  If a test technician could damage the PCB when they are placing it in the test fixture, Cage Blocks are used to safely guide the UUT onto the probe plate’s tooling pins.  In the functional test fixture shown, both cage blocks and tooling pins are used to register the device under test to the fixture.