Method and deadman test circuit for testing a functionality of a shearing blowout preventer. The circuit includes a solenoid valve configured to be electrically controlled and to receive a fluid under a first pressure; a sub plate mounted valve configured to be hydraulically controlled by the solenoid valve and to receive the fluid under a second pressure; and a selector valve fluidly connecting an output of the sub plate mounted valve to a shearing blowout preventer and to a device. The selector valve is configured to be operated by an operator.