Dell 5110CN error message.

Have you tried resetting the printer?  Try admin menu,maintenance,reset defaults

This may reset other things as well, so make sure you know your settings. Otherwise it may clear the jam.

Is there a small remnant of paper still in the printer?  That causes this as well.

.... Thinkpads_User

I restored the default settings, no good.   I installed a new MPT feed roller today to try to correct a paper jam problem withe the MPT tray.   Is it possible I need to do something with that part of the printer to reset something that thinks there is still a paper jam?

It has been a long time since I had a client with that Dell Printer, and I cannot answer the last question.

Try this link below on resetting that part.

http://en.community.dell.com/support-forums/peripherals/f/3528/t/18647276.aspx

... Thinkpads_User

but there is no paper in the printer to cause a jam.

There may be a small piece of paper stuck somewhere in the paper path. This can happen if paper gets scrunched up and then tears when it is pulled out. This can happen especially at the paper detector sensors. These can be optical sensors, or tiny switches with a plastic flag that is pushed aside by the paper. Paper can rip at those, especially when it is pulled backwards. Paper should always be pulled forwards when clearing a jam.

Alternatively, one of the flags may have been pulled off altogether.

Have a good look through the printer. If you know where the last jam was, start looking in that area.

I've requested that this question be closed as follows:

Accepted answer: 0 points for DoctorK12008's comment #a39161094

for the following reason:

Found my own solution.

the Actuator's shaft had come adrift from its holder

That was one of my suggestions: "one of the flags may have been pulled off altogether"