Plotter printing wrong colors

[cadmatic]

I am using AutoCAD 2014. I have just purchased a HP1050c plotter and had it worked over by a reputable service company. It prints all test pages beautifully. The problem I am having is that grays print yellow, some greens print yellow also. Basic colors seem to print OK. I am not sure if it is an AutoCAD setting, plotter setting, or printhead issue. The service guy doesn't know much about AutoCAD so he wasn't much help. I have tried different drawings and settings and it always prints any shade of gray in yellow. I am not finding any related topics on the internet. The grays in this drawing are the architectural background for a piping isometric drawing. Nothing is XREF. Can someone please give me some pointers. Thanks in advance to all who reply.

[ReMark]

Every plotter has the ability via Printer Properties to print a test page. Have you used this feature? Do all colors print as expected?

 

Are you experiencing similar issues with color prints when using other Windows programs?

[RobDraw]

You did not mention AutoCAD pen settings. Have you checked them?

[eldon]

Does AutoCAD still ship with the Color Wheel drawing? That should give the printer a good workout.

[cadmatic]

We solved this problem. The answer was the driver. I had trouble finding a driver for this old plotter in Windows 7 version. It prints beautifully now. Thanks to everyone for the reply's. I'd be lost with out all of you.