King Air 350 GNS 530 or second GPS monitor not working?

[captainmd]

Hi All,

Anyone know what would cause the Garmin GNS to stay "OFF" after the avionics switch is turned on? I comes on for 5 seconds then turns off. I looked in the manual and I could not find anything about it.

I am using the PMS 50 for the GTN750 and for the GNS 530.

Thanks in advance for any advice!!

[Yoda967]

At the upper left side of the GNS 530 bezel, there's a small, round switch marked "C". This should turn the unit on.