Xerox 7800 DN trouble with paper size and warming

Hi! When i strarted printer, he is write, that there is a warming up. And the heating continues indefinitely.
Plus printer doesn't suggest defining paper parameters. He is see, what i put paper into the tray 1 or tray 2, but i can't specify the dimensions, colour and density of paper. In logs have a next troublecode:  389.603.00, 389.601.00, 375.100.00  What does it mean?