Lexmark c544dn leaves yellow toner on my papers

Probably dropping from Magenta cartridge.Try replacing toner.

It is important to have toner in each of the toner cartridges, even if you don't use that color at all. The machine periodically `calibrates' by putting a very small amount on a belt in the machine. If it is unable to calibrate, it won't get ready.
Also, if you run an empty toner cartridge for too long, it will begin to leak waste toner, and cause major problems.

Check the transfer belt and clean if necessary with Isopropanol (IPA), and a soft clean cloth. Also check the drum for the same. Handle with extreme care as these are fragile and expensive. If none of those fix the issue you may need to get the laser lenses cleaned professionally.

Pull back the fuser cover ( black upper area) and look for the jam beneath the black roller with paper sticking up - to pull it out

The link provided below illustrates the location of the waste toner box and how to replace it. http://bitly.com/qq4DJ0
You may Lexmark Technical Support for further assistance.

Please try the steps provided below.

Step Action 1
Power off the printer/MFP and open the toner access door. Reseat all of the toner cartridges. Power on the printer/MFP again and print a test page.
Did the error message return?
Yes: Continue to Step 2.
No: The error is resolved. 2
Power off the printer/MFP and remove the developer unit for the color specified in the error message, and then reseat it. Power on the printer/MFP again and print a test page.
Did the error message return?
Yes: Continue to Step 3.
No: The error is resolved. 3
It is possible that specified color's toner cartridge and developer unit are defective. If you have a replacement toner cartridge and developer, install them as a test and print a trial page.
Did the error message return?Yes: Continue to Contacting Lexmark.
No: The error is resolved. If the toner and/or developer were not near the end of their working life.
You can also refer to this link: http://bit.ly/kecjEM

Please click on the link http://bit.ly/psOcDA to see instructions on how to go about the procedure.

For further assistance, please contact Lexmark Technical Support.

You have to replace your toner box. You can purchase the waste toner box at Lexmark.com
Here's the part number:C540X75G
If you need further assistance, please contact Lexmark Technical Support Center.

Go to this website and order a new waste toner bottle. It will have instructions on replacing it. It is very simple.
http://www1.lexmark.com/products/view/Multifunction/C54x,-X54x-Waste-Toner-Bottle/catId=cat10008-category&prodId=4584-product

Try to reseat the waste toner box and power down the printer for at least 30 seconds.
If you need further assistance, please contact Lexmark Technical Support Center