Printer Goes Offline After ~3.5 Hours

I have a client with two Epson wide format printers. One of them is older, an SC P5000, and it works perfectly. Nothing weird there. They got a new printer, an SC P9000 a while back. Ever since, it goes offline every 3.5 hours. It requires a power cycle and it'll come back online and work normally. We've had an Epson tech check the sleep settings and replace the internal board, he says there's nothing wrong with the printer. I configured the printer to use DHCP, and it's connecting to a print server (Windows). It has a DHCP reservation. It's shared out from the print server to the rest of the

Question by Hungry Giraffe on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.