Epson ET 2800 printing gibberish

[Mr. Z]

I received a grant to buy an Epson ET 2800 color printer for my elementary school library. The kids are excited to be able to print in color. Our district tech support team doesn't support outside printers, though, and they won't allow me to connect it to our wireless network at school. So when the firmware needs updating, I have to take it home and connect to my home wifi to update it. At school I have to connect via USB directly to my PC. Recently, however, the moment I plug in the printer's USB cable to my PC, the printer starts printing gibberish symbols filling up the page. There are no queued print jobs. It just starts on its own. I've tried restarting, resetting, updating the software at home. It seems like an update issue, but I don't really know. Does anyone have a suggestion for me? Thanks.