Abstract: A top access test probe fixture (10) for use with a vacuum-actuated primary test fixture (12) includes a probe block (70) supported for reciprocal movement on a contact board (54) mounted on the movable top platen (28) of the primary test fixture. The probe block (70) is actuated through bellows (86) disposed between the probe block and contact board (54), which bellows are connected in fluid communication with the vaccum chamber of the primary test fixture (12) so that the top access test fixture (10) is actuated simultaneously and responsive to actuation of the primary fixture. Contacts (102) are provided on the contact board (54) for engagement with probes (104) on the primary fixture (12) and probes (100) on the probe block (70) connected by leads (106) to other probes (108) on the probe block adapted for engagement with predetermined points on the top of the circuit board under test to avoid bending and thus fatigue and breakage of wires during operation.