I have a large sign and the entire sign is displaying random lights.

This is most likely an error with a Receiver Card. Larger displays tend to have multiple Receiver Cards located throughout the sign.

The first thing to do is restart the sign. Then, if the sign is not fixed, put a test pattern on the sign. Finally, take a picture of this test pattern and email it to the support staff at Datatronic Control, Inc.

The Technical Support email is: support@dcisign.com