Unresponsive interface ZPrinter 310

Hello world!

We have a ZPrinter 310 whose interface has become unresponsive. After bringing the printer offline for internal maintenance, we can no longer get it back online. The Build, Feed, Spread, and Online buttons no longer facilitate any action by the machine but the Power light is still lit green. As far as we can tell, all of the wiring appears to be in order and the ribbons are in good shape. Has anybody had this issue and overcome it?

Thank you in advance.