MML16CN weird signs

Hi everyone,

I’ve found an old message board (MML16CN) in my basement and wanted to see if it would still work. After plugging it in I say this:

And when I try to upload a message from my computer, it blink but stays the same. And my computer gives this error:

Every button on the controller only gives a beep. (Only the on/off button works properly)

Does anyone know what might cause this and how I can fix it?