GNS 530 Does not turn on in Caravan

[Bigmarty]

Good morning. I had no AP in the Black Square 208. As shown somewhere in the forum I changed the wording in the Working-title file and the AP now seems to work.

But I no longer have the GNS 530 (blank screen). Have installs from Marketplace and Content Manager, have un-installed and reinstalled the 208 more than once, have tried with nothing in the Community folder except the black square 208.

It works in other aircraft.

Need the GNS 530 - any suggestions would be great TIA.