What was found
WHILE DEMONSTRATING THE FUNCTION OF THE CABIN BAROMETRIC SWITCH TO A TRAINEE, IT WAS FOUND THAT WHEN POWER WAS APPLIED TO THE SOLENOID ON THE BAROMETRIC SYSTEM, THE OXYGEN VALVE DID NOT OPEN AND DROP THE MASKS. TROUBLESHOOTING FOUND A VOLTAGE DROP AT THE CIRCUIT BREAKER. WHEN THE C/B WAS REPLACED, THE SYSTEM WORKED AS ADVERTISED. THERE IS NO FUNCTIONAL TEST OF THE ELECTRICAL PORTION OF THE OXYGEN AUTO DEPLOY SYSTEM, BUT IT MIGHT BE A GOOD IDEA TO PERFORM IT WHEN THE BARO VALVE IS OVERHAULED IN 24 MOS.