To perform the following steps, you will need to have local administrator access to your PC and/or domain admin access (depending on how your network is set up). If you do not, contact your network administrator or Desktop Support Specialist for assistance.
The first thing I would do since it's a network printer is ping the IP address to make sure it's connect to the network. You can do this by opening a command prompt by going to Start > run and typing cmd and pressing ok or by hitting start and then type cmd in the seach field (vista/windows 7).
Type the following:
Ping <ip address of the printer>
Then press enter. If you get 100% packet loss to the printer, check the network cable connected to the printer to make sure it's plugged in on both ends and troubleshoot from there to make sure the printer is in fact receiving an IP address from the DHCP server. If it's set up statically then make sure you default gateway is correct. If you are running any sort of VLAN's make sure they are allowed through the appropriate networks.
If you ping the printer and it successfully went through, go into Start > Settings > Printers and Fax's (or various versions of this in Vista/Windows 7) and remove the printer. Reinstall the printer using the IP address for the port and make sure you are installing the most up to date driver. I have included a link at the bottom of this for the most up to date driver for your model.
http://onyxftp.mykonicaminolta.com/download/SearchResults.aspx?productid=1156&osid=3
Have a great day.