GTN750Xi not turning on after plane startup

[thatdfwspotter]

Hello,

We will gladly help you, but you will need to let us know of the problem that you are experiencing, please give us as many details as you can.

Well when I try to use it in for example to black square baron I have selected the correct instrument from the switches but when I go to power on the aircraft it just has a black screen it is connected I check on the TDS GTNXI flight sim software and I has a green status symbol. and says connected to flight sim but when I try to flick any of the knobs or try to attempt to click the volume/power knob it doesn't do anything. I tried to look at past posted but didn't really understand, thanks.