Printer Kills Itself After Connecting to Network

We have a Sharp MX-2610N printer than is connected to our LAN. The printer is shared on our server so that staff can print to it. It has been connected for a long time and has worked perfectly. 2 days ago, it stopped receiving print jobs. There have been no recent software or hardware changes (that I know of).

Pinging from the server and switch got the message " destination host unreachable". When you restart the printer, it will be pingable and you can print from it for about a minute and then it loses connection until you restart it again. We do not use subnets, but we do have two switches connected together to expand available ports.

When I disconnected it from our LAN and connected directly to my laptop, it never lost connection and I could print as much as I wanted.

I also tried different ethernet cables and switch ports and nothing...