How do I get the printer from off line to ready

The printer is warming up and is not ready to accept data. Wait until the printer signals ready. If necessary, press On Line.

the red light (online error) means that the printer is off line. How do you fix it? you press the "ok" or "reset" button and it puts it back on line and ready to print.

It means that, for some reason, the computer can't find the printer it where it expects it to be or else the printer is not ready to print. This can happen if it's turned off, unplugged, or in a non-ready state (such as a paper jam, etc.).

Richt click on the printer icon and make sure use printer off line is not checked.

The computer reports the printer as being offline because it cannot "see" the printer. Make sure the printer is turned on, that the computer is connected to the printer (either with a cable or wireless), and that the printer isn't displaying any error condition on its control panel.

try with test print
change the property of offline (untick)
check for any other printer installed on the computer

Dose the printer show up under printers and faxes? Dose it show the words ready or work off line under the printer? If the printer shows work off line, right click the printer and take the check away from work off line. It should change the wording to ready and start printing.

unplug it for a little while

Start the Konica Minolta Status application and check the error, you should get more info there.

Reset your Toners and Imaging units for Bizhub and CF series.
http://www.chipreset.eu

You can try to do a "Cold reset"

turn off the printer hold down  the Menu/reset button and turn it back on.

Do you hear the machine go into rotation? the 4 plus has a high pitch sound follwed by the fuser turning ( you'll know when it does it) if it doesn't go into rotation then there is another problem.