Accion 2. Switch off senographe and the place board 400-pl7 on the extender. connect (-) of voltmeter to - of capacitor C32, and connect (+) to common point of resistor R6 and collector (pin 7) of optocoupler B2 of 400 -pl7. Switch on generator. Voltage measured should be 0.09 V +- 50 mV. Led DE4 of 400 -PL3 should be lit and +5V of lambda power supply should be present on 400-pl7 board. If required, replace optocoupler B2.