Problem with network printer

Hi, I have a Kyocera Mita FS-3800 connected via TCP/IP to the network, when there are a few users in the net the printer works fine, but if all the users are connected and somebody send to print, the printer shows “F3 – Call service person”. First I thought it was a problem with the printer, and I tried to conneccting another printer, but the second printer also showed the error “call services person” (without the “F3”). Now I think is a problem with the network, but I don’t know what to do. Thanks!